Excessive nitrogenous fertilization in years resulted in larger nitrogen and profit losses. This problem can be reduced by using need-based and time-specific nitrogen management. Therefore, a field experiment was carried out during the Kharif season of 2019 and 2020 in order to evaluate the impact of precision nitrogen management on the phenology, yield and agrometeorological indices of hybrid maize genotypes at the Agronomy Research Farm, FoA Wadura, Sopore, SKUAST-Kashmir. The experiment was carried out in split-plot design consisting of maize hybrids (Shalimar Maize Hybrid-2 Vivek-45 and Kanchan-517) as main plot treatments and precision nitrogen management (T1: Control, T2: Recommended N, T3: 25% N as basal ≤ LCC 3@20 kg N ha−1, T4: 25% N as basal ≤ LCC 3@30 kg N ha−1, T5: 25% N as basal ≤ LCC 4@20 kg N ha−1, T6: 25% N as basal ≤ LCC 4@30 kg N ha−1, T7: 25% N as basal ≤ LCC 5@20 kg N ha−1 and T8: 25% N as basal ≤ LCC 5@30 kg N ha−1) as sub-plot treatments. Results demonstrated that maize hybrids showed a non-significant difference in attaining different phenophases during both years. However, Shalimar Maize Hybrid-2 demonstrated higher grain (62.35 and 60.65 q ha−1) and biological yield (170.26 and 165.86 q ha−1), a higher number of days to attain different phenological stages in comparison to Vivek-45 and Kanchan-517 thereby achieved higher heat units, PTUs, HTUs, PTI. The application of nitrogen through LCC ≤ 5@30 kg N ha−1 noted higher grain yield (61.27 and 59.13 q ha−1) and biological yield (171.30 and 166.13 q ha−1) during 2019 and 2020 respectively. Higher values of Growing degree days (GDD), Heliothermal units (HTU), Photothermal units (PTU), Phenothermal index (PTI), heat use efficiency (HUE) and radiation use efficiency (RUE) were observed in the application of nitrogen through LCC ≤ 5@30 kg N ha−1 and required the highest number of days to reach different phenophases than other treatments during crop growing seasons of 2019 and 2020. The results demonstrated that Nitrogen application based on LCC ≤ 5@30 proved effective and should be adopted in maize hybrids especially in Shalimar Maize Hybrid-2 to attain higher yield under the temperate climate of Kashmir Valley.

https://www.mdpi.com/2073-4395/12/12/2981/pdf?version=1669864629

Leaf Color Chart (LCC)-Based Precision Nitrogen Management for Assessing Phenology, Agrometeorological Indices and Sustainable Yield of Hybrid Maize Genotypes under Temperate Climate

Climate change has a major impact on crop yield all over the world. Pakistan is one of the major affected countries by climate change. The agrometeorology indices were determined for the South Punjab region, which is a hot spot for climate change and food security. This region is rich in agriculture, but crop yield relationship is estimated with agrometeorology indices (AMI). Temperature stress (33°C), average diurnal temperature range (12°C), Average accumulative growing degree days (1303°C), phototemperature (27°C) and nyctotemperature (21°C) indices were determined for Multan. The variation in diurnal temperature was found at 0.39 for Bahawalpur region and similar variation was observed in growing degree days, which is 0.11 more than the diurnal temperature range. The extreme of these indices which influence the crop yield was found in May and June. The cropping period from sowing to harvest varied due to climate change and cause to decrease in the yield of the crop. The indices are regarded as crop performance indicators. So, policymakers and agricultural scientists should take necessary measures to mitigate such kinds of challenges. 

Temperature Based Agrometeorology Indices Variability in South Punjab, Pakistan

An experiment was conducted to evaluate the effect of the age of a seedling and sources of nutrients on the growth and yield of sweet corn at SKUAST-K during Kharif-2020. The experiment was performed under a factorial arrangement in a randomized complete block design (RCBD) with three replications. Factor A was the age of the seedling with three levels, viz., 12-day-old seedlings, 22-day-old seedlings, and 32-day-old seedlings. Factor B was the source of nutrients with five levels, viz., control, recommended dose of fertilizer (RDF), 1/2 RDF + 12 t ha–1 farmyard manure, 1/2 RDF + 4 t ha–1 vermicompost, and 1/2 RDF + 2 t ha–1 poultry manure. The experiment was tested using variety Sugar-75 with a spacing of 75 × 20 cm2. The findings of this study indicated that the age of the seedling and sources of nutrients extended a significant influence on growth parameters, yield attributes, and yield of sweet corn. Significantly highest values for various growth parameters of sweet corn, viz., plant height, number of functional leaves, leaf area index (LAI), and dry matter accumulation from 30 days after transplanting up to the harvest, were noted by transplanting A2 seedlings (22 day old). A similar trend was observed for yield attributes and yield with higher values with transplanting A2 seedlings (22 day old). Plots fertilized with 1/2 RDF + 2 t ha–1 poultry manure registered a significantly higher plant height, leaf area index (LAI), dry matter accumulation, and number of functional leaves, which eventually resulted in a higher green cob yield and green fodder yield under the same treatment. Overall, this study indicated that among different ages of seedlings, transplanting A2 seedlings (22 day old) outperformed other seedling ages, and plots treated with 1/2 RDF + 2 t ha–1 poultry manure outperformed other treatments; a combination of both proved superior in realizing a higher yield and profitability with a benefit–cost ratio (BCR) of 6.57 under temperate climatic conditions.

https://pubs.acs.org/doi/pdf/10.1021/acsomega.3c01518

Munazah Yaqoob

Papers

Evaluation of seedling age and nutrient sources on phenology, yield and agrometeorological indices for sweet corn (Zea mays saccharata L.)