Crop yield response to deficit irrigation imposed at different plant growth stages

Author(s):  
T. Kovacs ◽  
G. Kovacs ◽  
J. Szito
Agriculture ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 826
Author(s):  
Johnnie van den Berg ◽  
Carmen Britz ◽  
Hannalene du Plessis

Fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), is a major pest of maize. Yield losses between 30 and 70% in the Americas and between 11 and 100% in Africa have been reported. Little information exists on the effect of pest damage during different plant growth stages on yield loss. Previous studies showed that insecticide applications at weekly intervals did not always provide a yield gain comparable to only a single or two well-timed applications. In this study, we completed four field trials under high natural pest pressure. Treatments consisted of different regimes of insecticide applications that provided protection against damage during different growth stages. In one trial, the mean incidence of infested plants was 65%, and the yield benefit gained from four insecticide applications was 32.6%. The other three trials had 16 treatments which were divided into two spray sequences to protect plants against FAW damage for different lengths of time, between early vegetative stages and tasseling. Yield losses were 41.9, 26.5 and 56.8% for the three respective trials if no insecticides were applied. Yield loss of plants protected during earlier growth stages was significantly lower than that of the treatments which provided protection during later growth stages. More than three spray applications generally completed did not provide further yield gains. Plants that were protected more during early growth stages yield higher than plants protected during later growths stages.


2021 ◽  
Author(s):  
Shu Wang ◽  
Dao-Wei Zhou

Abstract The relationships among developmental stability, canalization and phenotypic plasticity have not been well understood. Inconsistent conclusions from different studies suggested the complexity of their associations, probably depending on specific traits, environmental contexts and plant growth stages. To address this issue, we conducted three experiments (EXP I ~ III) with several annual herbaceous species, to investigate the relationships among leaf (or cotyledon) developmental stability, canalization and plasticity and their variations with different biotic and abiotic environmental conditions and plant growth stages, with comparisons among different species at their early growth stage. We analyzed variations in mean trait value, lamina fluctuating asymmetry (FA), coefficient of variation (CV) and plasticity (RDPIs) and their correlations for lamina size (LS) of individual plants, for LS, petiole length (PL) and petiole angle (PA) of different plant layers in Abutilon theophrasti at three densities in infertile and fertile (or only fertile) soil conditions at three (or two) stages, and for cotyledon size (CS) of five species in contrasting light conditions and seeding depths. High vs. low density decreased LS (with negative RDPIs), FA indexes and CVs, either for individual plants or different layers, especially in fertile soil. Shading was more likely to increase CS (except for A. therophrasti) and FA and decrease CV; deep seeding increased CS of some species in full light, but decreased CS and FA of other species in shading (except for A. therophrasti). FA indexes more likely had positive correlations with mean value, CV and RDPIs of traits; correlations between CV and RDPIs can be positive, negative or insignificant. Correlations among the three variables were more likely positive or insignificant for traits of LS, CS and PL, but more likely negative or insignificant for PA. High density and infertile soil may favor more positive over negative correlations among variables. Results suggested higher levels of lamina FA more likely indicate higher growth rates of plants or modules. Developmental stability was more likely to have positive correlations with canalization, and negative correlations with plasticity, indicating certain common mechanisms associated with them. Environmental stresses can lead to greater phenotypic variations at different levels, facilitating cooperation between the three processes in dealing with environmental challenges.


2013 ◽  
Vol 85 (2) ◽  
pp. 813-822 ◽  
Author(s):  
LEONARDO B. DE CARVALHO ◽  
PEDRO L.C.A. ALVES ◽  
STEPHEN O. DUKE

Weed management systems in almost all Brazilian coffee plantations allow herbicide spray to drift on crop plants. In order to evaluate if there is any effect of the most commonly used herbicide in coffee production, glyphosate, on coffee plants, a range of glyphosate doses were applied directly on coffee plants at two distinct plant growth stages. Although growth of both young and old plants was reduced at higher glyphosate doses, low doses caused no effects on growth characteristics of young plants and stimulated growth of older plants. Therefore, hormesis with glyphosate is dependent on coffee plant growth stage at the time of herbicide application.


2010 ◽  
Vol 97 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Cyrus Mansouri-Far ◽  
Seyed Ali Mohammad Modarres Sanavy ◽  
Seyed Farhad Saberali

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7070
Author(s):  
Chenxu Liu ◽  
Hui Zhou ◽  
Jie Zhou

With the frequent occurrence of extreme climate, global agriculture is confronted with unprecedented challenges, including increased food demand and a decline in crop production. Nanotechnology is a promising way to boost crop production, enhance crop tolerance and decrease the environmental pollution. In this review, we summarize the recent findings regarding innovative nanotechnology in crop production, which could help us respond to agricultural challenges. Nanotechnology, which involves the use of nanomaterials as carriers, has a number of diverse applications in plant growth and crop production, including in nanofertilizers, nanopesticides, nanosensors and nanobiotechnology. The unique structures of nanomaterials such as high specific surface area, centralized distribution size and excellent biocompatibility facilitate the efficacy and stability of agro-chemicals. Besides, using appropriate nanomaterials in plant growth stages or stress conditions effectively promote plant growth and increase tolerance to stresses. Moreover, emerging nanotools and nanobiotechnology provide a new platform to monitor and modify crops at the molecular level.


2016 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Farid Kuswantoro ◽  
R.C. Hidayat Soesilohadi

Paddy field was a dynamic and biodiversity rich ecosystems. Insect diversity in paddy field ecosystem was infected by paddy plant growth stages. Grass frog (Fejervarya limnocharis) ate insects as their natural prey. Insect population dynamics during vegetative, generative and reproductive stage of paddy plants infected F. limnocharis natural prey. This research aims were to study insect diversity and F. limnocharis insect prey diversity of vegetative, reproductive and generative paddy plant growth stages at Panggungharjo village, Sewon, Bantul. Insect sampling was conducted by direct survey method while F. limnocharis collection conducted by Visual Encounter Survey (VES) method. Ninety eight insect species from 51 different families and nine orders of insect were found. The orders were Coleoptera, Diptera, Hymenoptera, Odonata, Orthoptera, Dictyoptera, Dermaptera, Hemiptera and Lepidoptera. Stomachs analysis indicated F. limnocharis ate nine insect orders. The orders were Coleoptera, Diptera, Hymenoptera, Orthoptera, Dictyoptera, Dermaptera, Hemiptera, Lepidoptera and Isoptera. Most commonly insect prey in vegetative, reproductive and generative phase paddy growth stage were the members of the Order Coleoptera, Family Acrididae (Orthoptera) and Family Formicidae (Hymenoptera) respectively. This study concluded F. limnocharis main natural prey was the easily found and easily perceived insects.


2010 ◽  
Vol 339 (1-2) ◽  
pp. 447-455 ◽  
Author(s):  
Yan Zhang ◽  
Bing-Hai Du ◽  
Zhi-gang Jin ◽  
Zheng-hua Li ◽  
Hong-ning Song ◽  
...  

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