The effect of some of the gibberellins (GA 3 , GA 4+7 und GA 13 ) on seed germination and subsequent seedling growth of Early Muscat grape was investigated. The after-ripened seeds were treated with 0, 50, 100, 250, 500 and 1000 ppm concentrations of each gibberellin. All gibberellins, except GA 4+7 , at concentrations beyond 50 ppm promoted germination. Generally, the lower concentrations were found more efficacious for enhancing the germination. GA 4+7 at 1000 ppm completely inhibited the germination. The activity of GA 3 was gradual and regular, whereas GA 4+7 and GA 13 showed swift activity with a narrow germination-promotive-concentrationrange. The variable influence of gibberellins an seedling growth was also observed. Der Einflus der Gibberelline GA 3 , GA 4+7 und GA 13 auf die Samenkeimung und das anschliesende Samlingswachstum bei der Rebensorte Early Muscat ( Vitis vinifera ) Bei der Rebensorte Early Muscat wurde der Einflus einiger Gibberelline (GA 3 , GA 4+7 und GA 13 ) auf die Samenkeimung und das anschliesende Wachstum der Samlinge untersucht. Die nachgereiften Samen wurden jeweils mit Gibberellinkonzentrationen von 0, 50, 100, 250, 500 und 1000 ppm behandelt. Alle Gibberelline, mit Ausnahme von GA 4+7 , forderten bei Konzentrationen uber 50 ppm die Samenkeimung. Im allgemeinen erwiesen sich niedrigere Konzentrationen hierbei als wirksamer. 1000 ppm GA 4+7 hemmten die Keimung vollkommen. Die Wirkungskurve des GA 3 in Abhangigkeit von der Konzentration verlief stetig und ausgeglichen, wahrend sie bei GA 4+7 und GA 13 einen raschen Anstieg mit einem schmalen keimungsfordernden Konzentrationsbereich zeigte. Auch beim Wachstum der Samlinge wurde der unterschiedliche Einflus der Gibberelline beobachtet.

Powdery mildew of mango (Oidium mangiferae Berthet.) is one of the major plant pathological constraints in growing successful healthy mango orchards. All the commercially cultivated varieties are susceptible to the disease. Dropping of flowers and immature fruits leads to serious crop losses to the mango growers. Keeping in view, an attempt has been made to manage the disease by exploiting the newly evolved fungicides. Triademefon 25 WP (0.05 %), benomyl 50 WP (0.1 %), hexaconazole 5 EC (0.05%), dinocap 48 EC (0.1 %), sulphur 80 WP (0.25 %) and penconazole 10 EC (0.05 %) were applied before flowering, during flowering and after fruit set from 2002 to 2004 cropping season to 16 years old mango cv. Dushehri at Punjab Agricultural University, Regional Fruit Research Station, Abohar located in the State of Punjab, India at 74.12 E, 30.08 N with an altitude of 185.78 meter with annual precipitation of 75-300 mm. All the fungicides were significantly effective in controlling the disease as compared to control. Penconazole, triademefon and hexaconazole proved significantly better in controlling the disease. However, penconazole excelled in checking the disease. In general, Triazole fungicides (penconazole, hexaconazole, triademefon) had shown their superiority in reducing the powdery mildew over non-triazole fungicides (benomyl, dinocap and sulphur).

The present studies were conducted on eight ber varieties during 2002 and 2003. Flowering in Chhuhara, Ellaichi, Sanaur No.2 and ZG-2 was initiated during last week of August; whereas Umran, Kaithli, Nazuk and Gola produced flowering during first week of September. Fruit set in all the eight varieties were observed during second week of October. Umran ripened in fourth week of March, whereas other varieties ripened in second week of March. Maximum fruit yield/tree; weight/fruit and size were recorded in Umran, whereas Sanaur No. 2 produced fruits with higher TSS and vitamin C content.

Fruit yield in Kinnow mandarin was improved significantly with increase in nitrogen dose alone and in combination with phosphorous and potassium. Maximum yield (525 fruits/tree; and juice content (53.57 %) with minimum peel thickness was recorded with the application of 1900g urea + 2730g superphosphate/tree treatment. However, maximum tree volume (72.84 m3) was observed with higher dose of Nitrogen (2850 g urea/tree). Fruit weight and and TSS/acid also increased with the application of different fertilizer doses. Maximum TSS/acid ratio (15.99) was recorded with medium dose (1900 g urea/tree) of N. Nitrogen and P status in the leaves improved with different doses of fertilizers and attained optimum range in the treatments having 1900g urea; 2850g urea and 2730g superphosphate. Application of 1900g urea + 2730g superphosphate was considered to be the best dose for achieving higher yield and better fruit quality in Kinnow mandarin grown under arid irrigated regions of Punjab.

The present investigation was undertaken with the object to standardise the optimum spacing and nitrogen application rate of Calendula officinalis L. The field trial was conducted with four planting densities viz., 30 cm × 20 cm, 30 cm × 30 cm, 45 cm × 30 cm and 45 cm × 45 cm and four levels of nitrogen viz., 0 kg N/ha, 60 kg N/ha, 100 kg N/ha and 140 kg N/ha. The experimental findings revealed that growth parameters like number of leaves, number of branches and leaf area per plant were maximum at lowest planting density (45 cm × 45 cm) and 100 kg N/ha, whereas the height of the plant was maximum at 30 cm × 30 cm and 100 kg N/ha. Early flower bud initiation was observed at a spacing of 30 cm × 20 cm and when nitrogen was not applied. Maximum flower diameter and average weight of individual cut flower were obtained at a planting density 45 × 45 cm with 100 kg N/ha. Cut flower and loose flower yield per plant were maximum when plants were spaced at 45 cm × 45 cm and supplied with 100 kg N/ha, whereas yield per unit area was more at highest planting density (30 cm × 20 cm) along with 100 kg/ha nitrogen.

Tree volume and stocldscion girth increased with the application of N alone @ 300 to 900 g/tree over control. Fruit yield (No. of fruitshee) increased significantly with the increase in nitrogen and in combination with phosphorus and potassium and recorded maximum in trees receiving N @ 900 g, P @ 300 g and K @ 300 g treatment. Average fruit weight, TSS and vitamin C contents increased with the application of N alone and in combination with P and K in comparison to control. Application of 900 g N, 300 g P and 300 g K was found to be best dose for higher fruit yield and better fruit quality for sweet orange cv. Jaffa.

A rootstock trial was laid out at Regional Fruit Research Station, Abohar, during 1969 on Mosambi sweet orange using eight rootstocks viz., Jatti Khatti, Kharna Khatta, Troyer, Carrizo, Rangpur Lime, Jambhiri, Pectinifera and Citrumelo. Troyer & Carrizo citranges and Citrumelo were found to be incompatible rootstocks for Mosambi. Upto February 1981, the trees budded on Rangpur Lime produced maximum volume (32.2m3) and higher fruit yield followed by Jatti Khatti. However, Pectinifera excelled all the rootstocks producing significantly more tree volume in February 1991, and this trend is still continuing. Mosambi trees budded on this rootstock showed significantly more survival (100%), stock (94.0 cm) and scion (96.5 cm) girth than that of Kharna Khatta, Jambhiri and Rangpur Lime rootstocks. Average fruit yield (1975 to 1996) of Mosambi cultivar was significantly more (252 to 312 fruits/tree) on Pectinifera than the rest of the rootstocks tried. Pectinifera produced significantly higher TSS (9.8%) and less peel (25.2%) content in Mosambi fruits as compared to that of all other rootstocks.On the basis of these results, it may be concluded that upto the age of 12 years Rangpur Lime, and afterwards upto 28 years age of the trees, Pectinifera rootstock is suitable for commercial cultivation of Mosambi sweet orange under arid-irrigated conditions of Punjab.

A rootstock trial using Jatti khatti, Kharna khatta, Troyer, Carrizo, Rangpur lime, Pectinifera, Cleopatra and Citrumelo rootstocks for Blood Red cultivar of sweet orange was planted in 1968. Results obtained upto 1990 revealed that Jatti khatti performed better for the first 12–13 years age of the trees due to high vigour and better fruit yield. After 1983, trees of Blood Red raised on Jatti khatti started dying and by 1990, only 59% trees survived; whereas on Cleopatra all the trees survived. Tree volume was 36.1 m3 on Jatti khatti against 64.1 m3 on Cleopatra rootstock during 1990. The trees on Jatti khatti rootstock showed only 21% healthy trees with lower mean yield (181 fruits/tree) compared to Cleopatra which showed cent per cent healthy trees with more mean yield (265 fruits/tree) upto 1990. The trees of Blood Red budded on Cleopatra rootstock had better fruit quality compared to those on Jatti khatti.

Three cultivars of ber, viz. Sanaur No. 2, Umran and ZG2 grown at Regional Research Station, Ballowal Saunkhri were analysed for fruit yield, growth characteristics and their physico-chemical properties. Among these, Sanaur No. 2 was found most promising for cultivation under rainfed conditions in the lower Shiwaliks of Punjab.

Six cultivars, viz. Flordasun, Partap, Prabhat, Shan-i-Punjab, Florda Red and Sharbati were evaluated for their flowering behaviour, fruit yield, quality attributes and insect-pest incidence. Partap, Prabhat and Flordasun were observed to be earliest (4th week of April) to reach maturity and thus are suitable for the arid-irrigated region of Punjab. Florda Red and Sharbati were not suitable since they were late in maturity and moderate to highly susceptible to fruit fly incidence.

A rootstock trial was conducted on Marsh Seedless cultivar of grapefruit, using Jatti Khatti, Kharna Khatta, Troyer and Carrizo as rootstocks. The results of 20-year trial revealed that the trees budded on Troyer and Carrizo (citranges) rootstocks produced 100% survival with all the trees in healthy condition; whereas Jatti Khatti and Kharna Khatta showed only 50 and 17% survival of the trees respectively. Both the citranges also showed significantly more stock or scion girth and tree volume than Jatti Khatti rootstock. Significanlty more mean fruit yield from 1986–87 to 1996–97 was observed on Troyer and Carrizo rootstocks than on Jatti Khatti. Mean results of fruit-quality attributes showed that TSS percentage was more on Troyer than on Jatti Khatti root-stock. Heavier fruits with less peel percentage were also recorded on Troyer and Carrizo citranges than on Jatti Khatti rootstock.

Studies were carried on six almond varieties namely California Papershell, Pethick's Wonder, Hybrid-15, JK Selection-55, JK Selection-77 and JK Selection-167; planted in January 1986, to evaluate them for their performance under arid-irrigated conditions of Punjab. Maximum tree survival was obtained in Pethick's Wonder and Hybrid-15 varieties, and the minimum in JK Selection-77. Significantly more stock and scion girths were recorded in JK Selection-157 than that noted in Hybrid-15 and JK Selection-55. Significantly more fruit yield was noted in California Papershell and Hybrid-15 than that found in all the other varieties during 1994. In 1995 and 1996, JK Selection-167 produced significantly more fruit yield than that noted in all the other varieties. Mean yield from 1994 to 1996 was found maximum in JK Selection-167 followed by Hybrid-15 and California Papershell. Pethick's Wonder produced maximum average fruit weight and kernel weight (14.0 g and 7.1 g, respectively). JK Selection-167 showed the minimum (5.40%) leaf infestation by mite during the three years of study.

Effect of various herbicides viz. diuron, simazine, atrazine, weedone, dalapon and dalapon in combination with gramoxone was studied on the mineral composition of leaves and fruit quality of sweet orange cv. Blood Red. The nutrient status of leaves was profoundly influenced by various herbicides while no significant effect was observed on the physico-chemical characteristics of the fruits. Nitrogen, phosphorus and potassium content increased in all the herbicidal treatments. Zinc content in the leaves increased though it remained in deficient range, whereas iron content decreased. No consistent trend was observed in the manganese content of the leaves.

Plant growth regulators, GA3, 2,4-D, NAA, urea were sprayed on 10 year old kinnow mandarin trees to control physiological fruit drop. The maximum check of fruit drop was observed with 2,4-D (20ppm) spray application closely followed by GA3 (15ppm). Maximum juice per cent, TSS: acidity ratio observed in 2,4-D spray treatment. 2,4-D thus proves effective for control of physiological fruit drop.

Studies were carried out with six almond varieties, namely, California Paper Shell, Pethick's Wonder, Hybrid-15, JK Selection-55, JK Selection-77 and JK Selection-167 for their suitability in arid-irragated region of Punjab. Maximum plant survival (92.7%) was noted in California Paper Shell followed by Pethick's Wonder. Both these varieties showed maximum scion/stock ratio of plants. Initiation of flowering was observed on 11th February in California Paper Shell, which came to full bloom on 25/26 February with 15 days flowering duration. Pathick's Wonder showed longest flowering duration of 19 days from 14th February to 5th March but showed the shortest fruit set duration of only 11 days. Mass flowering in all the varieties, except JK Selection-167, overlapped from 14th February to 25th February and are thus recommended for planting together to obtain good fruit set.