Influence of heat stress on yield and its components of some early maturing bread wheat genotypes under Middle Egypt conditions.

Abstract

Nine bread wheat early maturing promising lines and three local cultivars were evaluated at Mallawy Agric. Res. Stations, ARC, Egypt, for the two successive growing seasons of 2018/2019 and 2019/2020 under the two sowing dates, the recommended (SD1:30 th November) and the late sowing date (SD2:30 th December). A split-plot arrangement with three replicates was used in each season. The aim of this study was to select the best genotypes for early maturity and higher grain yield. The results showed significant differences among genotypes for all studied traits in the optimum sowing date (SD1) compared to late sowing date (SD2). The optimum sowing date (S1) produced the highest values for all studied traits in both seasons, while the late sowing date (S2) was recorded the earlier plants for heading and maturity dates. The studied genotypes differences significantly in all estimated traits, lines 1 and 2 had the earliest genotypes for heading days, while Giza 171 and line 8 were the latest one for this trait. On the other hand, lines 9 and 4 were the earliest genotypes for maturity date, while the latest one was recorded for Giza 171. Line 5 surpassed all the other genotypes in grain yield (28.31 and 23.17 ard. fed -1 ) in the first and second seasons, respectively and it is appeared to be more tolerant to late sowing date as well as heat stress. The interaction (SD x G) had a significant effect on most studied traits. Lines 9 and 6 were the earliest genotypes for maturity when sown on 30 Nov. also, lines 9 and 4 were the earliest genotypes when sown on 30 Dec. The highest grain yield was obtained from line 4 followed by line 5 when sown on 30 Nov. and line 5 had the highest grain yield when sown on 30 Dec. in the first season. While, in the second season, lines 5 and 8 recorded the highest grain yield when sown on 30 Nov. and 30 Dec. respectively. Line 5 is suitable for planting in a wide range of planting dates (from 30 th Nov. to 30 th Dec.). Moreover, it is early maturing and can be recommended for late sowing (30 th Dec.). Therefore, the results of the present study confirmed that lines 4, 5, 7 and 6 were superior over the other genotypes in producing the earliest maturity date and higher grain yield and can be used, in future, in bread wheat breeding programs for the development of wheat cultivars for high temperature stress condition at the terminal growth stage.

Impact of Planting Date and Physiological Activator (Appetizer) Application on Quality and Quantity of Wheat Grains (Triticum aestivum.L)

“…Photosynthesis between the main stem and the ribs formed in the early stages of growth .The reason for this is the death of the branches before full maturity due to the lack of nutritional components on the date of 15/11, the appropriate climatic conditions and the length of the vegetative growth period reduced competition between the main stem and the tillers, which led to the formation of fertile tillers. This is in agreement with [32,43,44], who pointed out the short period of vegetative growth due to high temperatures when planting wheat late causes the short time available for the formation of the head starters in the formed shores. On the one hand, Other suitable environmental conditions for a period of growth sufficient for the transformation of a greater number of vegetative shores into head-bearing shores.…”

“…The data in Table 8 showed that there were significant differences in the weight of 1000 grains at planting dates and spraying treatments and the interaction between them, as the evidence recorded high values for the average weight of 1000 grains when planting on the first appropriate date, which amounted to 36.26 g, compared with the average of this trait when planting on the second late date, which amounted to 32.80 g, the appropriate climatic conditions such as temperatures and lighting period that were available to the plant on the first date led to an increase in the output of photosynthesis and the availability of food and the lack of competition for it due to the long period of vegetative growth, which reflected positively on the fullness of grain. As for the climatic conditions that were available for the plants on the second date, they did not It is appropriate or ideal as in the first date, so the temperatures rose and the lighting period increased, which led to an acceleration of vegetative growth, which in turn reduced the photosynthetic products from the nutrients resulting from the vegetative parts due to the low values of chlorophyll that led to the yellowing of these parts and exited from the building process in plants, which This reflected negatively on the fullness of grain, and this is consistent with the study of [32,44,48] ,who indicated that a A delay in the cultivation of wheat leads to a reduction in the length of the grain's filling period as a result of high temperatures during the grain's filling period, which caused the rapid yellowing of stems and leaves and the cessation of photosynthesis products in those vegetative parts, which reduced the supply of grains with representation products, causing a decrease in their weight. Including Table 8, which occurred when spraying wheat on the leaves in the stages of growth development, showing the importance of the physiological stimulant and its efficiency in regulating the growth of the plant, especially at the double spray stages, as the data recorded the highest average weight of 1000 grains when spraying the leaves of plants in the elongation and booting stage, which amounted to 40.07 g compared to With plants whose leaves were not treated at any stage, the average weight of 1000 grains reached 30.47 g. The reason for the increase in the values of this trait is due to the increase in the efficiency of the roots in absorbing the elements and raising the content of chlorophyll in the vegetative parts of the plant due to the presence of minerals in the activator such as zinc and manganese and the increase in the metabolites Photosynthesis that increases the fullness of the bean and thus increase the weight of 1000 beads and this is in agreement with [47,49,50].The treatment of plants with different concentrations of biological stimulants increases the weight of 1000 grains, and the reason for this is due to the role of algae as a bio fertilizer in increasing the total chlorophyll and enhancing the physiological activities in plants, which is reflected on the photosynthesis activity and the traits of plant growth, as for the interaction between planting dates and spraying stages with physiological stimulant Table 8 indicated that there were significant differences, as the value of the weight of 1000 grains recorded an increase in the treatment of plants by spraying on the leaves at the elongation and booting stages at the first ap...…”

Effect of sowing date on grain yield and quality of some Egyptian bread wheat genotypes

“…Desta et al, (2020) who reported that selection of suitable crop genotypes according to the agroclimatic conditions may play crucial role in realizing the optimum production of any crop commodity. The differences due to the interaction between sowing date and genotype in all studied traits except for grain yield were like those observed by ), Hasina et al, (2012, Munsif et al (2015), Yusuf et al (2019) and Ahmed (2021).…”

Effect of Planting Date and Spraying with the Physiological Stimulant (Appetizer) on the Growth and Yield of Wheat (Triticum aestivum.L)

“…This coincided with [44], which indicated an increase in the length of the spike due to the time of spraying algae fertilizer, which created conditions that reduced competition between plant parts and thus increased the effectiveness of photosynthesis in providing carbon metabolism products during the short period preceding the emergence and development of the spike that It coincides with the early growth stages of the plant's life, such as branching and elongation, which is one of the largest development stages in the life of the wheat crop, which was positively reflected in the increase in the length of the spike. Also [45,46] , indicated that the use of seaweed fertilizers with certain concentrations increases the length of the spike. The results of Table 6 showed that there is a significant difference for the interaction between planting dates and spraying dates for the trait of spike length, The results recorded the highest spike length when plants were treated with the physiological stimulant in the elongation and booting phase at the first date, which amounted to 12.57 cm, compared with the treatment without spraying at the second date, which recorded the lowest spike length of 9.85 cm.…”