随着我国城镇化率的提高以及老龄化问题的加重,"谁种地"成为我国目前亟待解决的问题.而农业生产托管可以通过单环节托管、半托管、全托管等模式,让专业的社会化组织帮助农民解决种地问题.本文从目前农业生产托管现状、农业生产托管经营方式比较以及农业生产托管经营模式等方面进行论述,并提出了今后农业生产托管的发展对策.

乡村要振兴,农业必定先振兴.农业现代化是实现乡村振兴的必然要求.农业现代化的基础是种子现代化,种业处于农业产业链的源头,是国家战略性、基础性的核心产业,是促进农业长期稳定发展、保障国家粮食安全的根本所在.近几年,我国先后出台了一系列种业发展相关政策文件,连续多年中央一号文件都聚焦现代种业发展,将现代种业工作摆在重要位置,为种业体系建设保驾护航.

以美国大速生生菜为试验材料,研究绿天、益丰源、绿神保3种微生物菌肥对生菜生长和品质的影响.结果表明:3种微生物菌肥均能在适宜浓度下不同程度地促进生菜生长,改善生菜品质,降低硝酸盐含量,而高浓度微生物菌肥会抑制生菜生长,低浓度则无显著影响.3种微生物菌肥最适宜的施用浓度均为1∶300,促进效果为绿天＞益丰源＞绿神保.

Taking grafted seedings of Citrus reticulate 'Shatangju'on rootstock of trifoliate orange as material,the determination effects of I2-KI,TTC,MTT and in vitro pollen germination method were compared and their effect on in vitro activity of pollen between the different types of flower(the flower with leaves and non-leaf flower)of Citrus reticulate'Shatangju'were studied.The results indicated that the pollen of Citrus reticulate'Shatangju'viability of nonleaf flower was higher than the pollen viability of flower with leaves.MTT staining method was the optimum and rapid staining method to determine pollen viability of Citrus reticulate'Shatangju'.

This experiment was conducted with the effects of different concentrations of spermidine on Citrus reticulata cv Shatangju. The study includes pollen germination in vitro, development of ovary, fruit setting rate of Shatangju. The results showed that: exogenous Spd treatment can promote Shatangju's pollen germination and promote ovary development, improve the fruit setting rate under a suitable concentration, especially for non-leaf flower is more effective. Exogenous spd concentration of 50μmol/L is the best choice for two different types of flower on pollen germination, flower setting and fruit setting rate.

In order to study the effects of different shading treatments on the canopy microclimate condition, shoot growth and some leaf physiological metabolism of citrus under solar greenhouse, 4-year-old seedlings of Shatangju tangerine (Citrus reticulate ‘Shatangju’) on the stock of trifoliate orange (Poncirus trifoliata Raf.) was selected as materials. Results showed that the PAR and temperature of greenhouse were high, the relative humidity was very low, and the curve of diurnal variation of net photosynthetic rate ( Pn ) was demonstrated two peaks with midday depression of photosynthesis under un-shading treatment. Shading markedly decreased canopy PAR and temperature, increased the relative humidity. The curve of diurnal variation of net photosynthetic rate ( Pn ) was demonstrated single peak with shading. Shading inhibited the growth of new germination summer shoot. With the transmittance reducing, new shoot number, diameter and length decreasing. Shading markedly increased leaf area and decreased leaf thickness. Compared with CK, the Chl b of leaves declined and Chl a/b decreased under shading. The young fruit set with a layer of shading treatment increased 16.44%, while the young fruit set was 0 under two layers of shading treatment.

By the methods of principal component analysis,subordinate function,and cluster analysis,a comprehensive evaluation was conducted on the low ground temperature-resistance of 14 physiological indices of twelve marigold cultivars.The results indicated that the different tomato varieties of 14 physiological indicators in different degree, showing in the low ground temperature stress, the physiological indices exists between certain synergy and meet resistance. Six principal factors presented86.27% of the information of the 14 indices. The comprehensive evaluation value of the low ground temperature-resistance of the12 cultivars was in the order of'CM78''Toward the research' 'CM966' 'Gold beautiful' 'win beauty ' 'Vegetarian in 4' 'Prosperous powder' 'Gold crown a number' 'And within 3' 'Gingko strong abundant' 'Pink tomato''gold 168'.