Agroforestry is seen as a strategy to sustainably boost agricultural production by creating favorable microclimatic conditions. However, tree shade can significantly reduce crop yield, making it important to assess the balance between the positive and negative impacts of tree cover on food security, especially as climate change alters weather patterns. To understand this relationship, a trial was conducted to evaluate how tree canopy influences crop yield in degraded soils. This study examines how different levels of natural tree shade affect the physiological and biophysical constraints of soybean (Glycine max) in an Emblica officinalis-based agroforestry system. The study assessed the effects of shade intensities (S1-0

Crop adaptation to waterlogging stress necessitates alterations in their morpho-physiological and biochemical characteristics. Cowpeas, which serve as a dual-purpose legume crop (food and fodder), are sensitive to waterlogging stress, especially when exposed to extended periods of water stagnation during the early growth stage. In this study, we subjected five distinct and superior cowpea varieties to 10 days of waterlogging stress at the early seedling stage (V2, 15 days post emergence for 10 days) under controlled conditions. The aim was to comprehend the response of these varieties and identify the ideal trait for screening a large collection of cowpea genetic resources for waterlogging tolerance. We measured and analyzed changes in morpho-physiological and root parameters to gain a deeper understanding of the mechanism underlying waterlogging tolerance. The treatment (waterlogging and control), genotype, and their interactions had a significant impact on the most studied traits (p < 0.05). The results indicated a significant reduction in morpho-physiological parameters such as plant height, leaf area, leaf number, Normalized Difference Vegetation Index (NDVI), chlorophyll content, and chlorophyll fluorescence parameters under stress treatment than control conditions. However, root parameters like the number of adventitious roots (AR) and their length (ARL) significantly increased under waterlogging stress in tolerant cowpea varieties like DC15 and PL4. Correlation and PCA analyses further revealed a positive and significant association between cowpeas’ waterlogging tolerance and AR formation and its AR length. Therefore, the current study reveals that swift development of AR and ARL may serve as potential traits conferring waterlogging tolerance in cowpeas. Using suitable mapping populations, these traits could reveal genomic regions associated with waterlogging tolerance in cowpeas. The tolerant varieties and key traits identified in this study could be beneficial in breeding programs aimed at enhancing waterlogging tolerance in cowpeas.

Chickpea, a nutritionally rich annual legume predominantly cultivated in drought-prone regions, relies on photosynthesis for biomass production and grain formation. The resilience of this process is crucial for productivity under water stress, which induces leaf desiccation. In this study, 15 Cicer accessions from various species were assessed for deficit moisture stress tolerance based on photosystem-II (PS-II) efficiency during 30 h of gradual leaf moisture loss. A significant 33.26% reduction in the maximum quantum efficiency of PS-II was noted as absolute leaf moisture content (ALMC) decreased by 67.79%. Chlorophyll fluorescence-based imaging tools, known for their efficacy in screening genotypes for drought tolerance, revealed PS-II tolerance to tissue dehydration as a reliable indicator. Notably, Cicer accessions viz ., WC-02 (ICC17126), WC-08 (ICC17141), and CH-05 (ICC2580) exhibited higher tolerance, evident through elevated ALMC, increased proline content, and sustained PS-II efficiency. The optimized method demonstrated in this study holds promise for assessing Cicer accessions’ deficit moisture stress tolerance.

As the best-fit leguminous crop for intercropping across time and space, mungbean promises to sustain soil health, carbon sequestration, and nutritional security across the globe. However, it is susceptible to waterlogging, a significant constraint that persists during heavy rains. Since the predicted climate change scenario features fewer but more intense rainy days. Hence, waterlogging tolerance in mungbean has been one of the major breeding objectives. The present experiment aimed to employ non-destructive tools to phenotype stress tolerance traits in mungbean genotypes exposed to waterlogging and estimate the association among the traits. A total of 12 mungbean genotypes were used in the present study to assess waterlogging tolerance at the seedling stage. Plant responses to stress were determined non-destructively using normalized difference vegetation index (NDVI) and chlorophyll fluorescence parameters at different time intervals. NDVI and grain yield were positively associated with control (r = 0.64) and stress (r = 0.59). Similarly, chlorophyll fluorescence (quantum yield of PS-II) also had a significant positive association with grain yield under both control (r = 0.52) and stress (r = 0.66) conditions. Hence, it is suggested that NDVI and chlorophyll fluorescence promise to serve as traits for non-destructive phenotyping waterlogging tolerance in mungbean genotypes. With the methods proposed in our study, it is possible to phenotype hundreds of plants for waterlogging tolerance efficiently.

Capacity of mango tree to withstand drought (absence of soil moisture) can be attributed to stress resilient physiological processes inside the cell and also at whole plant level. To test this hypothesis, photosynthetic traits were recorded over the period of time. Further, desiccation tolerance of photosystem II (PSII) in excised mango leaves were measured by employing chlorophyll fluorescence imaging system. Beside this, the capacity of mango tree to keep its canopy cool was monitored in every 10 min interval throughout the day during dry and rainy season in the field by employing thermal imaging system. Finally, phenomics platform was used to monitor depletion of tissue moisture level as well as changes in structural attributes during desiccation in excised shoots of the tree. It was inferred that mango tree can maintain its carboxylation efficiency over the period of time. IR studies confirmed that mango tree maintained its canopy coolness during dry season. In addition, the chlorophyll fluorescence experiments revealed that mango leaves retained 50% of initial PSII efficiency for as many as 4 days after desiccation and chlorophyll fluorogram also depicted the observations. Phenomics studies concluded that mango twig retained tissue water content even up to the 164 h of desiccation with gradual decrease in canopy area. Hence, it is interpreted that these physiological resilience are amongst the various reasons for evergreen feature of mango tree which has tendency to survive severe soil moisture deficit particularly during the summer in tropical and subtropical regions, which has been revealed for first time using phenomics platform.

Dryland fruit crops are highly prone to stresses caused by depleting soil moisture coupled with high ambient temperatures, particularly during summers. This is more conspicuous and seldom deleterious during droughts, which recur periodically. However, some of the crops sustain and recover their growth after the drought. Since desiccation of leaf is one of the consequences of depleting soil moisture and high temperature, we predicted that those crops that can maintain their photosynthetic efficiency during such stresses could outperform others. We hypothesised that the variation exists in the sensitivity of Photo system II (PS-II) component of the photosynthesis system among the dry land fruit crops. A series of experiments were conducted for assessing the desiccation responses of leaves of six fruit crops by employing chlorophyll fluorescence imaging, which reveals PS-II efficiency. As expected, there was a drastic reduction in the maximum quantum efficiency of PS-II (QYmax) of leaves of all the fruit crops with the decrease in tissue water content. However, there were significant differences among the crops in their responses to the desiccation of leaves. The PS-II tolerance to tissue dehydration observed in karonda (Carissa carandas L) and sweet orange (Citrus sinensis),was higher than that of mango (Mangifera indica L) and grape (Vitis vinifera L). This study reveals the method to assess the sensitivity of fruit crops to desiccation, which can be useful in water management, and in assessing the efficacy of novel chemicals for alleviating abiotic stresses.

Infrared (IR) imaging, chlorophyll fluorescence imaging and plant phenomic approach were used to study physiological mechanism of desiccation tolerance in Azadirachta indica and Terminalia mantaly during the period of November 2018 to February 2019. IR imaging instrument was installed in the field for monitoring the canopy temperature dynamics of different canopy level including stem region of the tree throughout the day. Maximum photochemical efficiency (F-v/F-m) was measured with chlorophyll fluorescence measuring system for sun exposed leaves of A. indica and T. mantaly over a period of desiccation. In order to reveal complete understanding of physiological mechanism of desiccation tolerance, plant phenomic approach was used for assessing response of these tree species to exposed desiccation. Results indicated that canopy temperature of upper foliage, lower foliage, stem (trunk) region of A. indica were quite higher during the hotter period of the day as compared to T. mantaly and maximum photochemical efficiency (F-v/F-m) was maintained in A. indica leaves as compared to T. mantaly for same exposed duration of desiccation. Plant phenomic approach also depicted that A. indica twig retained more tissue water and maintained canopy volume area higher than T. mantaly. Thus it provides an indication that A. indica tree is quite desiccation tolerant than T. mantaly by maintaining its canopy temperature, maximum photochemical efficiency, more tissue water and canopy area.