Early Yield Research Articles

Cinco ciclos de seleção recorrente intrapopulacional em progênies de meioirmãos de milho fresco

ABSTRACT Fresh corn is a highly appreciated vegetable in Brazil; this crop has high added value and profitability when compared to dry corn. Despite the consumer market demand for quality, cultivars are not launched every crop season and there is a small number of cultivars available to growers. This denotes a need for breeding programs focused on generating information and genotypes that can occupy this market niche. The objective of this work was to evaluate the progress of five cycles of intrapopulation recurrent selection in half-sib progenies of fresh corn, in the southwest region of Goiás. A randomized block experimental design was used, with evaluation of 64 progenies of corn half-sib progenies and selection intensity of 30% per cycle, with three replications, in the 2011-2012, 2013-2014, 2015-2016, 2017-2018, and 2020-2021 summer crop seasons. The half-sib progenies of fresh corn exhibited genetic variability through intrapopulation recurrent selection in the different selection cycles, which is still promising for further selections after five cycles, with evaluation of 64 progenies per cycle. The base population from crossings between hybrids for tropical and temperate climates showed to be promising for increasing the genetic base of fresh corn populations, with satisfactory gains over the five cycles, presenting mean heritability between the cycles of approximately 78.9% for relative chlorophyll index, 62.2% for plant height, 75.1% for ear insertion height, 70% for ear diameter, 56.6% for ear length, 71.4% for unhusked ear yield, and 71% for marketable ear yield.

Hydrogen Cyanamide Application Accelerates Vegetative Bud Break and Causes Earlier Yield in ‘Optimus’ and ‘Colossus’ Southern Highbush Blueberry

Southern highbush blueberry (Vaccinium corymbosum interspecific hybrid) cultivation is a major industry in subtropical regions where low winter temperatures are infrequent and inconsistent. In Florida and other subtropical areas, growers use hydrogen cyanamide (HC) applications during endodormancy to mitigate the negative effects of low chill accumulation. Hydrogen cyanamide is a synthetic plant growth regulator that increases and expediates dormancy release and budbreak. However, southern highbush blueberry cultivars differ in their sensitivity to HC. Optimus and Colossus are two recently released cultivars from the University of Florida blueberry breeding program. The effects of HC in these cultivars are unknown. This research aimed to describe responses to HC applications at different rates for these new varieties. Experiments took place in a commercial farm in Waldo, FL, on 3- to 4-year-old deciduous blueberry bushes. HC was applied at rates of 3.8 g·L−1 (0.38%), 5.1 g·L−1 (0.50%), and 6.4 g g·L−1 (0.63%) in ‘Optimus’ and 3.8 g·L−1 (0.38%), 5.1 g·L−1 (0.50%), 6.4 g·L−1 (0.63%), and 7.7 g·L−1 (0.75%) in ‘Colossus’. In both cultivars, the control treatment was not sprayed. Vegetative bud count, and flower bud development, flower bud mortality, and yield were determined. HC application thinned reproductive buds and increased vegetative budbreak. Although seasonal yield was not increased, HC advanced fruit ripening early in the season.

Evaluation of the Relations between Yield and Yield Components of Tomato (Solanum lycopersicum L.) Hybrids by Correlation and Path Analysis

Tomato is one of the most produced vegetables in the world and there are many plant breeding studies that are carried out on this vegetables species. One of the most important aims of tomato breeding is the improvement of fruit quality and yield in both open-field and greenhouse growing conditions. The knowledge of factors with regard to yield is making plant breeders work easier. In the present study, the correlations of some plant characteristics thought to be related to yield and their direct and indirect effects on yield were analyzed. This study was conducted with 14 genotypes in 2020 and a randomized complete block design was employed as an experimental design. The relationship between 12 traits and yield was determined through path coefficient analysis. It was determined that the number of days from the first fluorescence to the first fruit set time, the length under the first cluster, fruit length, fruit diameter and Brix° value have a directly negative effects on the yield. However, fruit weight, fruit number, leaf diameter, and early yield have a directly positive effect on the yield. However, early yield had a directly positive effect on the yield. According to the result of this study, in the correlation matrix, the number of days from first fruit set time to fruit ripening, internode length, fruit diameter, leaf diameter, leaf length and number of fruit per plant are insignificant. The obtained results a potentially be utilized as selection criteria in the future studies on yield.

Effect of Plant Extract and Plant Hormonal Accessories on Growth and Yield Tomato

A field experiment was carried out inside a plastic house in (Al Bandar region) second research station in College of Agriculture / Al-Muthanna University scince winter season 2020-2021, to study the effect of two factors : first one was auxin (IAA) : control (T0), 1 ml. L-1 (T1), and 2 ml. L-1 (T2), second factor was a mixture of licorice extract with yeast suspension: control (F0), 5 g.L-1(T1) and 10 g.L-1(T2). A Completely Randomized Block Design ( R.C.B.D.) were used with three replicates and means were compared according to L.S.D. test at the level of 0.05. Results showed that Significant superiority of auxin treatment at 2 ml.L-1 in the characteristics of plant height (73.0 cm), number of leaves (25.89 leaves), leaf area (15.21 dcm2), early yield (1.91 kg.Plant-1) and number of fruits (44.78 fruits.Plant-1), while the concentration exceeded 10 g.L-1 of licorice extract and yeast suspension in the two characteristics of leaf area and number of fruits (1345 cm2, 42.78 fruits) respectively. Results also indicated that the interaction of F2T2 had a significant increase in plant height(78.0cm), leaf area (15.17 dcm2).

Life cycle inventory of Miscanthus production on a commercial farm in the US.

There has been considerable interest in use of Miscanthus (Miscanthus x giganteus) as a feedstock for bioenergy production due to its potential to reduce greenhouse gas emissions associated with cellulosic feedstock production and more recently for alternative uses as a biomass crop. To date, data on Miscanthus production in the US has been based on small scale research plots due to the lack of commercial scale production fields. Research plot yields are often much higher than commercial fields for a variety of reasons including reduced spatial variability and location on better quality farmland. The objectives of this study were to quantify the inputs for production of Miscanthus at the commercial farm scale, evaluating methods to characterize fuel use for establishment and management of Miscanthus production and using satellite data to characterize spatial yield variation of production fields. We logged energy use on agricultural machinery from Miscanthus production planted on more than 1000 ha of land and modeled N2O emissions and changes in soil carbon using DayCent. Although fuel use was higher for land preparation in fields with perennial vegetation, fuel to harvest Miscanthus dominated greenhouse gas (GHG) emissions (>90%) from agriculture machinery for crop management. The N2O emissions and changes in soil carbon were the largest source and sink of GHG emissions associated with Miscanthus production, respectively. Although ~ 50% of the established lands had Miscanthus yields < 5 Mg/ha, yields needed to be > 5 Mg/ha for ΔSOC to be positive. Given the large impact of yield on ΔSOC, net GHG for Miscanthus production with yields of 5 to 25 Mg/ha ranged ~130 to -260 kg CO2e/Mg biomass. Use of both energy use for Miscanthus harvest and satellite imagery were good methods to characterize spatial variability of commercial production fields. This demonstrates the potential to use this within field yield data to better understand factors driving subfield yield variability and use of satellite data to quantify early yield predictions.

Doğu Akdeniz koşullarında ikinci ürün olarak yetiştirilen bazı hibrit mısır genotiplerinde tane ve yem verimi ile yem kalite özelliklerinin değerlendirilmesi

This research was conducted in order to guide farmers and researchers by determining grain, forage yield and yield-related traits and forage quality of different parts of the whole plant in some maize cultivars in Eastern Mediterranean ecological conditions. In this study, it was assessed grain and forage yield and fodder quality of four maize cultivars (PR91G98, SY Castaneda, SY Gladius, and SY Tuscani) cultivated under the Estern Mediterranean conditions. To determine forage quality, ear, stem and leaves of the whole plant maize were analyzed separately. To evaluate grain and forage yield, parameters like plant height, stem diameter, hay yield, dry matter yield, green leaf yield, green stem yield, ear weight, green ear yield were investigated while features such as crude protein, crude ash, organic matter, NDF, ADF, digestibility of dry matter, dry matter intake and relative feed value were examined to determine forage quality. The new maize cultivars have been updated continually; it is important to clarify the responses of new varieties to agronomic practices and forage yield, quality, grain yield, and related traits. The results of this study revealed that ear is very important for forage yield and quality. The greatest hay and grain yield were produced by PR31G98 maize cultivar. It was observed SY Tuscani had higher NDF and ADF values than other maize varieties. With this study, the importance of nutrient content according to silage yield and plant parts in second crop corn cultivation was determined. In addition, research results showed important source data for farmers and researchers regarding forage and grain yield of maize farming and production area is continually increasing.

Response of Broccoli to Mulching and Foliar Application of Licorice Root Extract and their Effects on Yield and Macronutrient Contents

The research was done in the vegetables research farm at the College of Agricultural Engineering Sciences at University of Dohuk, Kurdistan region of Iraq, during the growing season in (2021-2022). The reason behind the study was to investigate the response of two cultivars of Broccoli (Brassica oleracea var. italica.) Ajjasi and Wisdom cv. to different types of mulching (without, black plastic and straw) and also the different concentrations levels of licorice root extract (0, 6, 12 and18g.L-1) on productivity and some nutrients content of Broccoli curd. The results showed that Wisdom cultivar performed better than Ajjassi in terms of early yield and nutrients content. Throughout the research season, both cultivars were considerably improved in all examined attributes. Additionally, it was shown that all features in both cultivars were noticeably enhanced in plastic mulch. There was an observed increase in the majority of features of the interactions between licorice root extract and straw. Early yield in Wisdom cultivar was meaningfully different from Ajjasi (27.814 and 24.138) ton. ha-1 respectively. Most of the measurements were greatly influenced by black plastic mulch, while the best overall outcome was achieved in black plastic mulch and 18g.L-1 concentration of licorice root extract in Ajjassi cultivar. In both cultivars, there were noticeable changes in the nutrient’s contents of (Nitrogen, phosphorus, potassium %). In general, the combination among treatments was significantly enhanced in the all studied traits.

Spraying exogenous hormones alleviate impact of weak-light on yield by improving leaf carbon and nitrogen metabolism in fresh waxy maize.

Insufficient light during the growth periods has become one of the main factors restricting maize yield with global climate change. Exogenous hormones application is a feasible measure to alleviate abiotic stresses on crop productivity. In this study, a field trial was conducted to investigate the effects of spraying exogenous hormones on yield, dry matter (DM) and nitrogen (N) accumulation, leaf carbon and N metabolism of fresh waxy maize under weak-light stress in 2021 and 2022. Five treatments including natural light (CK), weak-light after pollination (Z), spraying water (ZP1), exogenous Phytase Q9 (ZP2) and 6-benzyladenine (ZP3) under weak-light after pollination were set up using two hybrids suyunuo5 (SYN5) and jingkenuo2000 (JKN2000). Results showed that weak-light stress significantly reduced the average fresh ear yield (49.8%), fresh grain yield (47.9%), DM (53.3%) and N accumulation (59.9%), and increased grain moisture content. The net photosynthetic rate (Pn), transpiration rate (Tr) of ear leaf after pollination decreased under Z. Furthermore, weak-light decreased the activities of RuBPCase and PEPCase, nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in ear leaves, and increased malondialdehyde (MDA) accumulation. And the decrease was greater on JKN2000. While ZP2 and ZP3 treatments increased the fresh ear yield (17.8%, 25.3%), fresh grain yield (17.2%, 29.5%), DM (35.8%, 44.6%) and N (42.5%, 52.4%) accumulation, and decreased grain moisture content compared with Z. The Pn, Tr increased under ZP2 and ZP3. Moreover, the ZP2 and ZP3 treatments improved the activities of RuBPCase, PEPCase; NR, GS, GOGAT; SOD, CAT, POD in ear leaves, and decreased MDA content during grain filling stage. The results also showed the mitigative effect of ZP3 was greater than ZP2, and the improvement effect was more significant on JKN2000.

Modeling of fertilization on the photosynthetic and yield indicators of melon (Cucumis melo L.) under the saline soils of southern Kazakhstan

Recommendations on the use of generalized regional fertilizers for agricultural crops lead to low fertilizer efficiency, and an imbalance of plant nutrition while identifying economic and environmental problems. The use of innovative methods with the modelling of fertilizers with balanced doses of nutrients used based on the needs of crops, the potential of fertility and the degree of soil degradation should be the main condition for sustainable precision farming. Therefore, a field experiment to study the application of mineral fertilizers on melon was carried out under two saline backgrounds of light serozem at a farmer’s field, Maktaaral District, Kazakhstan during 2022. The experiment was laid out in a randomized complete block design (RCBD) with 10 treatments: T1–Control (no fertilizer), T2–N120P80, T3–N120K80, T4–P80K80, T5–N120P80K80, T6–N60P80K80, T7–N180P80K80, T8–N120P120K80, T9–N120P80K120 and T10–N157K256 and N93K96 for a targeted yield of 30 and 20 t/ha on low and medium-saline soils, respectively, each replicated thrice. Ammonium nitrate (34%), double superphosphate (45%) and potassium sulfate (51%) were used as fertilizers. The study of photosynthetic productivity of plants showed that the accumulation of dry biomass (from 1.9 to 10.37 t/ha) and leaf area (from 7.8 to 26.5 m2/ha) adequately changed with changes in doses and ratios of fertilizers. On the low salinity background, high early yields were provided by T5 and T10-10.1 and 10.9 t/ha, against a medium saline background, they were lower than low saline background of 1.7 and 2.3 t/ha, respectively. When modelling the effect of fertilizers on the formation of an early melon crop, the unilateral action of nitrogen fertilizers, the interaction of nitrogen fertilizer with potash fertilizer and the interaction of phosphorus fertilizer with the soil salt concentration have been excluded from the equation as insignificant (P less than 0.05).

Faba Bean (Vicia faba L.) Yield Estimation Based on Dual-Sensor Data

Faba bean is an important member of legumes, which has richer protein levels and great development potential. Yield is an important phenotype character of crops, and early yield estimation can provide a reference for field inputs. To facilitate rapid and accurate estimation of the faba bean yield, the dual-sensor (RGB and multi-spectral) data based on unmanned aerial vehicle (UAV) was collected and analyzed. For this, support vector machine (SVM), ridge regression (RR), partial least squares regression (PLS), and k-nearest neighbor (KNN) were used for yield estimation. Additionally, the fusing data from different growth periods based on UAV was first used for estimating faba bean yield to obtain better estimation accuracy. The results obtained are as follows: for a single-growth period, S2 (12 July 2019) had the best accuracy of the estimation model. For fusion data from the muti-growth period, S2 + S3 (12 August 2019) obtained the best estimation results. Furthermore, the coefficient of determination (R2) values for RF were higher than other machine learning algorithms, followed by PLS, and the estimation effects of fusion data from a dual-sensor were evidently better than from a single sensor. In a word, these results indicated that it was feasible to estimate the faba bean yield with high accuracy through data fusion based on dual-sensor data and different growth periods.

GO nanoparticles mitigate the negative effects of salt and alkalinity stress by enhancing gas exchange and photosynthetic efficiency of strawberry plants

Considering the potential use of nanomaterials, particularly carbon-based nanostructures, in agriculture, we conducted a study to investigate the effect of graphene oxide (GO) on strawberry plants under salinity and alkalinity stress conditions. We used GO concentrations of 0, 2.5, 5, 10, and 50 mg/L, and applied stress treatments at three levels: without stress, salinity (80 mM NaCl), and alkalinity (40 mM NaHCO3). Our results indicate that both salinity and alkalinity stress negatively impacted the gas exchange parameters of the strawberry plants. However, the application of GO significantly improved these parameters. Specifically, GO increased PI, Fv, Fm, and RE0/RC parameters, as well as chlorophyll and carotenoid contents in the plants. Moreover, the use of GO significantly increased the early yield and dry weight of leaves and roots. Therefore, it can be concluded that the application of GO can enhance the photosynthetic performance of strawberry plants, and improve their resistance to stress conditions.

Analysis of Relationship between Grain Yield and NDVI from MODIS in the Fez-Meknes Region, Morocco

Exploring the relationship between cereal yield and the remotely sensed normalized difference vegetation index (NDVI) is of great importance to decision-makers and agricultural stakeholders. In this study, an approach based on the Pearson correlation coefficient and linear regression is carried out to reveal the relationship between cereal yield and Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI data in the Fez-Meknes region of Morocco. The results obtained show strong correlations reaching 0.70 to 0.89 between the NDVI and grain yield. The linear regression model explains 58 to 79% of the variability in yield in regional provinces marked by the importance of cereal cultivation, and 51 to 53% in the mountainous provinces with less agricultural land devoted to major cereals. The regression slopes indicate that a 0.1 increase in the NDVI results in an expected increase in grain yield of 4.9 to 8.7 quintals (q) per ha, with an average of 6.8 q/ha throughout the Fez-Meknes region. The RMSE ranges from 2.12 to 4.96 q/ha. These results are promising in terms of early yield forecasting based on MODIS-NDVI data, and consequently, in terms of grain import planning, especially since the national grain production does not cover the demand. Such remote sensing data are therefore essential for administrations that are in charge of food security decisions.

一种改进型YOLOv4的田间麦穗快速检测方法

The automatic detection of wheat ears in the field has important scientific research value in yield estimation, gene character expression and seed screening. The manual counting method of wheat ears commonly used by breeding experts has some problems, such as low efficiency and high influence of subjective factors. In order to accurately detect the number of wheat ears in the field, based on mobilenet series network model, deep separable convolution module and alpha channel technology, the yolov4 model is reconstructed and successfully applied to the task of wheat ear yield estimation in the field. The model can adapt to the accurate recognition and counting of wheat ear images in different light, viewing angle and growth period, At the same time, the model volume with different alpha parameters is more suitable for mobile terminal deployment. The results show that the parameters of the improved yolov4 model are five times smaller than the original model, the average detection accuracy is 76.45%, and the detection speed FPS is two times higher than the original model, which provides accurate technical support for rapid yield estimation of wheat in the field.

Shading Stress at Different Grain Filling Stages Affects Dry Matter and Nitrogen Accumulation and Remobilization in Fresh Waxy Maize.

Shading stress caused by plum rain season, which overlapped with grain filling process of fresh waxy maize in Southern China, significantly affected crop productivity. In order to investigate the effects of shading at different stages after pollination on the yield, accumulation, and remobilization of dry matter and nitrogen (N) in fresh waxy maize, field experiments were conducted, including shading at 1-7 (Z1), 8-14 (Z2), 15-21 (Z3), and 1-21 (Z4) days after pollination in 2020 and 2021. The results showed that shading reduced the fresh ear and grain yield and increased moisture content in Suyunuo5 (SYN5) and Jingkenuo2000 (JKN2000) compared to natural lighting treatment (CK). The ear yield decrease was more severe in Z4 (43.5%), followed by Z1 (29.7%). Post-silking dry matter and N accumulation and remobilization were decreased under shading stress, and those were lowest in Z4, followed by Z1. The remobilization of pre-silking dry matter and N were increased by shading stress, and the increase was highest in Z4, followed by Z1. The harvest index of dry matter and N was lowest in Z4 and second-lowest in Z1. In conclusion, shading decreased yield by affecting accumulation and remobilization of post-silking dry matter and N, and the impact was more serious when it introduced early during grain filling stage in fresh waxy maize production.

Stability Study of Cotton Genotypes Cultivated in Different Environments

In order to evaluate a group of cotton genotypes in different environments and study their genetic stability, thirteen cotton genotypes were tested, namely (ST468 - BA440 - DP396 - FLASH - EDESSA - Lashta - Cipro - Buck Cot 189 - IK259 - W888 - Coker 310 - Montana CANDIA). It was planted in Haditha district - Barwana district, by designing the Completely Randomized Design, according to the split-plot system and with three replicates. It was planted in six environments represented by planting distances of 7 cm and 14 cm between plants and three crop succession systems (cultivation after wheat crop, cultivation after barley crop, cultivation after fallow land) according to the no-tillage system and in the late cultivation, The study included eight traits: the number of fruiting branches, the total number of boll per plant, the number of open boll per plant, the number of seeds per boll, the average weight of the boll, the percentage of Earliness yield, the percentage of dressing and the yield of seed cotton. The results are summarized as follows: The study of genetic stability showed that the two cultivars (CANDIA and DP396) were distinguished by being stable and suitable for all different agricultural environments for the trait of seed cotton yield, The cultivars (BA440, FLASH, EDESSA and W888) were characterized by being stable and suitable for all different agricultural environments and for the traits of the number of fruiting branches, the total number of bolls, the number of open bolls, the number of seeds in boll and the average weight of bolls. The cultivars (BA440, FLASH, Lachata, Coker 310, and CANDIA) were characterized by being stable and suitable for all different agricultural environments and for the traits of the early percentage and the percentage of dressing. While the cultivar (EDESSA) was Earliness in yield and genetically stable.

Effect of fertilizers starter solutions on growth and production of broccoli (Brassica oleracea var. italica)

The seedlings of vegetables are exposed to stress states, especially through the first period, due to injuring their roots by transplanting or heavy rain , so it is necessary to provide an available nutrient to recover the growth and increase their early yield, which means more income for farmers. In this regard, an experiment was conducted in the College of Agricultural Engineering Sciences, Agriculture Faculty, University of Baghdad, Iraq to study the effect of different types and concentrations of mineral fertilizers as starter solutions by using high nitrogen (N), high phosphorus (P) and neutral fertilizers (Q) at three levels which were 4 g/l (S1), 8 g/l (S2) and 12 g/l (S3) on broccoli growth and yield. The results showed that the treatment of adding the starter solution of the neutral fertilizer with a concentration of 8 g/l (QS2 treatment) significantly enhanced the main head weight (631.9 g/plant), the plant yield (1050.6 g/plant) and the total yield (35.02 t/ha) traits, and gave good results for the indicators of quality characteristics of heads, where the percentage of soluble solids was 9.06 and the percentage of nitrogen and protein (3.72 and 23.25, respectively). Therefore, the addition of starter solution to the nitrogen fertilizer at a concentration of 8 g/l (NS2 treatment) enhanced the number and weight of lateral head which gave 7.28 lateral heads/plant and 420.9 g/plant, respectively.

A Pineapple Target Detection Method in a Field Environment Based on Improved YOLOv7

The accurate detection of pineapples of different maturity levels in a complex field environment is the key step to achieving the early yield estimation and mechanized picking of pineapple. This study proposes a target detection model based on the improved YOLOv7 to achieve the accurate detection and maturity classification of pineapples in the field. First, the attention mechanism SimAM is inserted into the structure of the original YOLOv7 network to improve the feature extraction ability of the model. Then, the max-pooling convolution (MPConv) structure is improved to reduce the feature loss in the downsampling process. Finally, the non-maximum suppression (NMS) algorithm is replaced by the soft-NMS algorithm, with a better effect at improving the detection effect when pineapple is in occlusion or overlaps. According to the test, the mean average precision (mAP) and recall of the model proposed in this paper are 95.82% and 89.83%, which are 2.71% and 3.41% higher than those of the original YOLOv7, respectively. The maturity classification accuracy of the model and the detection performance under six different field scenarios were analyzed quantitatively. This method provides an effective scheme for the vision system of the field pineapple picking robot.

Early Yield Forecasting of Maize by Combining Remote Sensing Images and Field Data with Logistic Models

Early forecasting of crop yield from field to region is important for stabilizing markets and safeguarding food security. Producing a precise forecasting result with fewer inputs is an ongoing goal for the large-area yield evaluation. We present one approach of yield prediction for maize that was explored by incorporating remote-sensing-derived land surface temperature (LST) and field in-season data into a series of logistic models with only a few parameters. Continuous observation data of maize were utilized to calibrate and validate the corresponding logistic models for regional biomass estimating based on field temperatures (including crop canopy temperature (Tc)) and relative dry/fresh biomass accumulation. The LST maps from MOD11A1 products, which are considered to be matched as Tc in large irrigation districts, were assimilated into the validated models to estimate the biomass accumulation. It was found that the temporal-scale difference between the instantaneous LST and the daily average value of field-measured Tc was eliminated by data normalization method, indicating that the normalized LST could be input directly into the model as an approximation of the normalized Tc. Making one observed biomass in-season as the driving force, the maximum of dry/fresh biomass accumulation (DBA/FBA) at harvest could be estimated. Then, grain yield forecasting could be achieved according to the local harvest index of maize. Silage and grain yields were evaluated reasonably well compared with field observations based on the regional map of LST values obtained in 2017 in Changchun, Jilin Province, China. Here, satisfactory grain and silage yield forecasting was provided by assimilating once measured value of DBA/FBA at the middle growth period (early August) into the model in advance of harvest. Meanwhile, good results were obtained in the application of this approach using field data in 2016 to predict grain yield ahead of harvest in the Jiefangzha sub-irrigation district, Inner Mongolia, China. This study demonstrated that maize yield can be forecasted accurately prior to harvest by assimilating remote-sensing-derived LST and field data into the logistic models at a regional scale considering the spatio-temporal scale extension of ground information and crop dynamic growth in real time.

Результаты испытаний новых полуштамбовых сортов томата в условиях Терско-Сулакской низменности Республики Дагестан

Abstract. The purpose of the research is to study the collection and breeding material of tomatoes with a determinant bush type in open ground conditions, and to identify the best samples based on the results of the research on economically valuable traits for their further use in tomato breeding. Scientific novelty. Recent events in the country show the need to study and recommend domestic tomato varieties and hybrids in safe and risky farming zones. The article presents a brief description of new domestic tomato varieties with a short growing season. Samples of morphological and biometric indicators for the source material of tomato breeding were selected. Varieties with short interphase periods “shoots –flowering”, “flowering – ripening” were identified. On the basis of a comprehensive assessment of early maturity, economically valuable characteristics and tasting evaluation of fruits, promising varieties were noted for recommendation and implementation in the production of the lowland and foothill parts of Dagestan. Methods. Field and laboratory. The method for the study was 8 new semi-stamp cultivars of VNIISSOK selection. Descriptions of tomato plants were carried out taking into account morphological (stem height, number of shoots, number of leaves, number of brushes, number of ovaries and fruits), agrochemical and complex of economically valuable characteristics (total and early yield, marketability of fruits, fruit weight, dry matter, sugar, fruit tasting evaluation). Results. According to the maturation dates, the samples were divided into three groups: very early – Severyanka, Blagodatnyy, Magnat, Voskhod VNIISSOKa (97–100 days); early – Patris, Viking, Perst (102–105 days); middle-early – Sodruzhestvo, Fakel (111–114 days). According to the type of bush, we have identified 5 ordinary and semi-lamb samples with a height of no more than 78 cm. Two samples had a height of 50.53 cm (Patris, Perst) and an average fetal weight of 72 and 60 g. Three samples had a height of 70, 71, 72 cm (Voskhod VNIISSOKa, Blagodatnyy, Sodruzhestvo) and an average fetal weight of 107, 110, 130 g respectively. According to the output of gross output, the best indicators were of the following varieties: Blagodatnyy – 86.3 t/ha, Voskhod VNIISSOKa – 82.7 t/ha, Sodruzhestvo – 77.6 t/ha, Patris – 68.2 t/ha. The following grades had a high yield of marketable products: Voskhod VNIISSOKa, Patris – 92 %, Blagodatnyy – 91 %, Perst – 90 %.

Effects of water deficit at different stages on growth and ear quality of waxy maize.

Extreme weather has occurred more frequently in recent decades, which results in more frequent drought disasters in the maize growing season. Severe drought often decreases remarkably plant growth and yield of maize, and even reduces significantly the quality of maize production, especially for waxy maize. To study the changes in plant growth, fresh ear yield, and fresh grain quality of waxy maize under water deficits occurring at different growth stages, and further strengthen the field water management of waxy maize, water deficit experiments were carried out under a rain shelter in 2019 and 2020. Water deficit treatments were imposed respectively at the V6-VT (DV6-VT), VT-R2 (DVT-R2), and R2-R3 (DR2-R3) stages of waxy maize, and treatment with non-water deficit in the whole growing season was taken as the control (CK). The lower limit of soil water content was 50% of field capacity for a water deficit period and 65% of field capacity for a non-water deficit period. In this study, water deficits imposed at V6-VT and VT-R2 stages decreased plant growth rate and leaf gas exchange parameters, accelerated leaf senescence, and limited ear growth of waxy maize, which resulted in 11.6% and 23.1% decreases in grains per ear, 19.4% and 7.3% declines in 100-grain weight, 20.3% and 14.2% losses in fresh ear yield in 2019 and 2020 growing seasons, respectively, while water deficit at R2-R3 stage had no significant effect on ear traits and fresh ear yield, but the fresh ear yield with husk of DR2-R3 decreased by 9.1% (P<0.05). The obvious water deficit imposed at the V6-VT and VT-R2 stages also lowered grain quality. Water deficits at the V6-VT and VT-R2 stages led to accelerated maturity, resulting in increased total protein, starch, and lysine content in grains at the R3 stage and decreased soluble sugar content. Principal component analysis revealed that when water deficits occurred in the waxy maize growing season, they firstly altered maize physiological processes, then affected ear characteristics and yield, and finally resulted in significant grain quality changes. In conclusion, a water deficit during V6-VT and VT-R2 not only reduced fresh ear yield but also adversely affected grain quality. However, water deficit during R2-R3 had little effect on total protein, starch, and soluble sugar content,but increased obviously lysine content. The above results suggested that avoiding serious water deficits at the V6-VT and VT-R2 stages of waxy maize while imposing a slight water deficit at the R2-R3 stage has not only little effects on fresh ear yield but also a remarkable improvement in grain quality.