Harvest Yield Research Articles

Effect of Boron and Zinc on Growth and Yield Attributes in Early Cauliflower (Brassica oleracea var. botrytis L.)

The present experiment was carried out in cauliflower to study the effect of boron and zinc on growth and yield in the early cauliflower having combinations of four levels 0, 1, 2, 3 kg ha-1 of boron and four levels 0, 2.5, 5.0, 7.5 kg ha-1 of zinc in a factorial randomized block design with three replications during the year 2016 and 2017 respectively. The results of the experiment with applied boron and zinc had significant effect on growth and yield of cauliflower. The highest curd depth (8.88 cm) and curd equatorial diameter (16.45 cm) was found with applied boron (2 kg ha-1) and zinc (2.5 kg ha-1) respectively. While as, maximum net curd weight (410g) and marketable curd weight (695g) was found with sprayed boron and zinc (1 kg ha-1 + 2.5 kg ha-1) respectively., Maximum harvest index (62.8 %) and yield (113.89 q ha-1) was found when applied with boron (2 kg ha-1) and (2 kg ha-1+ 2.5 kg ha-1) respectively. Maximum curd compactness (34.34) and dry matter compactness (14.48) were found with the application of boron (1 kg ha-1) and zinc (2 kg ha-1+2.5 kg ha-1) respectively. Overall findings indicated that with the increase in concentration of boron and zinc the vegetative growth and the reproductive stage of cauliflower increases respectively.

Community-supported agriculture as food democratic experimentalism: Insights from Germany

This paper analyzes community-supported agriculture (CSA) as a particular form of democratic experimentalism in food systems. Specifically, we explore both primary and secondary CSA initiatives in Germany, based on participatory observation on meetings and workshops, and on qualitative interviews. Opposing the industrial food system and market-based food distribution, CSA activists envision transformative change toward a sustainable, regionalized, and more democratic food system. A key feature of CSA as a specific form of alternative food organizations is its underlying collaborative effort among farmers and households: consumers take over production risks, make investments in their CSA and share crops, whereby they decouple producers' income from harvest yield and market prices. Employing a perspective that is informed by John Dewey's notion of democratic publics and experimentalism, we show that both on the primary and secondary levels as well as in collaboration with other political, economic, or civic actors, CSA is a manifestation of civil society's ongoing and never-ending inquiry to find joint solutions for their shared problems. We explore CSAs as democratic forms, in terms of their diverse internal structures and practices within the primary initiatives and also the secondary network. Furthermore, we reflect on their overall potential to democratize food systems. On all levels, we find the modus of experimentalism as the essential form of democratic inquiry. We show how the varying kinds of democracy that are embodied by primary initiatives differ from one another, and what kind of boundaries exist. These boundaries, inter alia, limit CSA's potential to achieve food democracy on a societal level, if democracy means giving everyone the opportunity to have a say whenever they are affected.

Incidence of dwarf disease and yield on Inpari 32 over two sequential seasons in Klaten, Central Java

Rice dwarf disease caused by Rice grassy stunt virus (RGSV) and Rice ragged stunt virus (RRSV) is frequently found in Indonesia. This disease is transmitted by brown planthopper/BPH (Nilaparvata lugens Stål). The infected plants become dwarfs and lead to reduced yields. The purpose of this study is to determine the number of BPH populations due to the occurrences of dwarf disease and yield on Inpari 32 rice over two sequential planting seasons in Klaten, Central Java. The observed parameters were dwarf disease symptoms, incidence and intensity of the disease, BPH population and its natural enemy, the vegetative growth, and yields. The analysis used in this study were descriptive analysis and linear regression. The results showed that, plant growth during the dry season was better than the rainy season based on plant height and tiller number. The average population of BPH in the dry season were 0.2–4 individual/hill which is lower than in the rainy season (0.43–4.4 individual/hill). The incidence and intensity of disease in the dry season were lower than rainy season. The higher incidence and intensity of rice dwarf disease in the rainy season caused a decrease in dry harvest yields and milled dry yields were 10.95% and 10.81%, respectively

Effect of organic and inorganic nutrient sources on growth, yield and economics of aromatic rice (Oryza sativa) in Gangetic delta of West Bengal

A field experiment was conducted at the Bidhan Chandra Krishi Viswavidyalaya, Jaguli, Nadia, West Bengal, during rainy season (kharif) 2019, to study the effect of different nutrient sources on growth, yield and economics of scented rice (Oryza sativa L.). Among 9 treatments, integrated nutrient management (FYM 4 t + N20P10K10 kg/ha) led to the maximum tiller production (345.4 /m2 ) at 56 days after transplanting (DAT), the highest leaf-area index (LAI) (2.90) and dry-matter production (596.2 g/m2 ) at 84 DAT. Chemical fertilizer-based nutrition (N40P20K20 kg/ha) resulted in the maximum plant height (125.0 cm) at harvesting and grain yield (2.57 t/ha), being at par with FYM 4 t + N20P10K10 kg/ha (2.53 t/ha). Plants in LCC-based N-fertilized plots had moderate grain yield (2.18 t/ha) and least lodging tendency (score 2.3). Chemical fertilizer-based nutrition could record the maximum yield (2.57 t/ha), net income (`42,126/ha) and benefit: cost ratio (2.02); but integrated nutrient management (FYM 4 t + N20P10K10 kg/ha) might be an alternative option for sustainable cultivation (2.53 t/ha, `38,069.50/ha and 1.86) in lower Gangetic plains of West Bengal.

Microalgal bioremediation of brackish aquaculture wastewater

Rapid aquaculture industry development contributed to a major increase in aquaculture wastewater generation. In the context of a circular economy, aquaculture wastewater treatment should simultaneously recover nutrients from the wastewater. Among many treatment methods, bioremediation using microalgae could be a cost-effective and environmentally friendly system that can be applied to treat aquaculture wastewater and simultaneously produce high-value microalgal biomass. This study explored the feasibility of treating brackish wastewater (0.8 % NaCl) generated from a Qatari commercial tilapia farm by microalgae. At first, 10 strains were grown using wastewater from the local farm in an indoor experiment. Based on nitrogen assimilation, biomass yield, biomass quality, and ease of harvesting, 4 candidate strains (Haematococcus sp., Neochloris sp., Monoraphidium sp., and Nostoc sp.) were shortlisted for outdoor growth experiments. Although Nostoc sp. could not grow outdoor in the wastewater, the other three strains were able to assimilate at least 70.5 % of the total nitrogen in the wastewater. Haematococcus sp. and Neochloris sp. could be harvested using self-settling, whereas Monoraphidium required an energy-intensive tangential flow filtration membrane process. Hence, the overall energy requirement for bioremediation, including biomass dewatering, for Haematococcus sp., Neochloris sp., and Monoraphidium sp. were determined as 0.64, 0.78, and 5.68 MJ/m3, respectively. Neochloris sp. had almost twice the biomass yield compared to Haematococcus sp. – suggesting that Neochloris sp. could be a potential candidate for aquaculture wastewater treatment.

E-BUSINESS TO SUPPORT SALES OF FARMER CROPS BASED ON MOBILE APPLICATIONS

The agricultural sector is essential because it is the leading sector and supports the Indonesian economy. Sukapura Village is one of the producers of plant products in the Kertasari District. But on the other hand, most of the farmers experienced problems, and several obstacles emerged, such as the accumulation of harvests that were sold at low prices, which resulted in losses, and the difficulty of distribution because it was pretty complicated. Of course, this situation must be improved so that people can enjoy Indonesian agricultural products. One of them is by building an android-based application "Petani Sejahtera" which is specifically made as an alternative to make it easier for farmers. It can break the distribution chain of agricultural products. You can directly contact the courier who has collaborated with the manager by displaying information on product price lists, farmers' products, and harvested products, which will later be distributed during the main harvest period. So that later, farmers will find it easier to see the products planted and do not have to think about how to distribute the products. The purpose of making this "Petani Sejahtera" Application is to help farmers more easily distribute their products to various suppliers, so there is no accumulation of harvest yields. The benefits generated have a positive influence, especially regarding the price of products produced by farmers following the "current" market price so that farmers do not experience losses and continue to increase their agricultural output.

Correlates of yield, fecundity and survival of a wild harvested Cyclopia intermedia (honeybush) population

ABSTRACT Cyclopia intermedia (honeybush) is a plant species endemic to the fynbos biome. Wild harvested populations are used commercially to produce tea. The species is a resprouter, regrowing from underground rootstock after fires, and as such resprouts once it has been cut. However, there is concern that premature cutting may be compromising rootstock recovery. We report on an initial 400 wild plants measured and monitored under different harvest regimes, including control plants. Plants were harvested once in 2018 and regrowth and survival monitored until 2021. Here, an allometric calculation is provided based on height and stem number to estimate the harvest yield. Plants in valleys or with high surrounding vegetation had the highest yield values and potential fecundity. After harvest, an increase in mortality was correlated with plant size, being higher for smaller plants, but after two years of drought high mortality was not explained by any harvesting category nor any of the site variables, suggesting drought results in high plant mortality regardless of harvest history. The study clarifies several speculative components of harvest method, demonstrates that a complete cut rather than half cut results in better potential yield, and that an ash admixture post-harvest had no measurable impact on regrowth.

Rainfall Prediction Rate in Saudi Arabia Using Improved Machine Learning Techniques

Every farmer requires access to rainfall prediction (RP) to continue their exploration of harvest yield. The proper use of water assets, the successful collection of water, and the successful pre-growth of water construction all depend on an accurate assessment of rainfall. The prediction of heavy rain and the provision of information regarding natural catastrophes are two of the most challenging factors in this regard. In the twentieth century, RP was the most methodically and technically complicated issue worldwide. Weather prediction may be used to calculate and analyse the behaviour of weather with unique features and to determine rainfall patterns at an exact locale. To this end, a variety of methodologies have been used to determine the rainfall intensity in Saudi Arabia. The classification methods of data mining (DM) approaches that estimate rainfall both numerically and categorically can be used to achieve RP. This study, which used DM approaches, achieved greater accuracy in RP than conventional statistical methods. This study was conducted to test the efficacy of several machine learning (ML) approaches for forecasting rainfall, utilising southern Saudi Arabia’s historical weather data obtained from the live database that comprises various meteorological data variables. Accurate crop yield predictions are crucial and would undoubtedly assist farmers. While engineers have developed analysis systems whose performance relies on several connected factors, these methods are seldom used despite their potential for precise crop yield forecasts. For this reason, agricultural forecasting should make use of these methods. The impact of drought on crop yield can be difficult to forecast and there is a need for careful preparation regarding crop choice, planting window, harvest motive, and storage space. In this study, the relevant characteristics required to predict precipitation were identified and the ML approach utilised is an innovative classification method that can be used determine whether the predicted rainfall will be regular or heavy. The outcomes of several different methodologies, including accuracy, error, recall, F-measure, RMSE, and MAE, are used to evaluate the performance metrics. Based on this evaluation, it is determined that DT provides the highest level of accuracy. The accuracy of the Function Fitting Artificial Neural Network classifier (FFANN) is 96.1%, which is higher than that of any of the other classifiers currently used in the rainfall database.

Role of Differential Nutrient Management on Growth and Yield Attributes of Cashew (Anacardium occidetale L.) in Maidan Tracts of Karnataka

The research on Nutrient Management for yield maximization in Cashew was conducted under Crop management, All India Co-ordinated Research Project (AICRP) on Cashew at Horticulture Research and Extension Centre, Hogalagere, Kolar district, Karnataka state, India during the period of 2020–21. There were six treatments imposed in the experiment, among the treatments, treatment-5 (T5) i.e ., cashew trees imposed with 100% RDF (500:250:250 g)+10 kg FYM along with foliar spray of major nutrients (3% Urea+0.5% MAP+1% K2SO4), secondary and micronutrients (0.5% ZnSo4+0.1% solubor as boron+0.5% MgSo4) was found significantly superior over remaining treatments in terms of growth parameters like Stem girth (17.91 cm), Canopy height (2.66 m), Canopy spread (E-W : 7.08 m except T4 and N-S : 7.12 m), Mean canopy diameter (7.10 m), Canopy surface area (158.55 m2 ) and ground area covered by plant canopy (61.99%). Whereas, T5 was also recorded significantly superior over other treatments and followed similar trend as in growth attributing parameters, such as Nut yield per tree (14.50 kg), Yield per hectare ( 18.87 q), Cumulative nut yield for six years of harvest (56.82 kg) and Cumulative yield per hectare (88.64 q). However the treatment-5 was also numerically elevated higher values in remaining all parameters and the lowest observation values were found in T6 (control). When look at the overall performance, treatment-5 (T5) was found to be best treatment.

Use of Endoscopic Vein Harvest Yields Improved Outcomes in Popliteal Artery Aneurysm Repair

There is growing literature showing that endoscopic vein harvest (EVH) is safe, with excellent patency rates and decreased wound complications when treating infrainguinal occlusive disease. Our institution has performed EVH since 2003 with a dedicated team of providers specializing in endoscopic vein harvest. The purpose of this study was to evaluate major outcomes of EVH as an adjunct to standard, open operative repair of popliteal artery aneurysms. We performed a 12-year retrospective single-institution chart review from January 2005 to December 2017, identifying all patients undergoing popliteal artery aneurysm repair with EVH. Primary outcomes were procedural technical success, operative time, wound complication, major morbidity, and freedom from amputation. A total 37 limbs (in 31 patients) received EVH popliteal artery aneurysm repair at an average age of 65.2±10years; 65% of the patients presented without symptoms or with claudication and 35% with rest pain or tissue loss. Coexisting aneurysm was present in 68% of patients: 49% had contralateral popliteal artery aneurysms and 19% had concurrent aortic aneurysms. Of 37 limbs, 33 (89%) were treated through a medial approach with aneurysm ligation, and 4 patients (11%) were treated through a posterior approach. The average vein size was 4.4±1.1mm, with 86% harvested by the ipsilateral great saphenous vein. Average operative time was 3.89±0.82hr, with a median hospitalization of 2days and a median of 1day of intravenous narcotics use. Only 2 patients (5.4%) had Szilagyi class-2 surgical site infections remedied with debridement and antibiotics. Kaplan-Meier data showed a 5-year primary patency of 82.3% and primary-assisted patency of 88.2%. Additionally, 30-day primary patency was 89.2% and primary-assisted patency of 97.3%. EVH for popliteal aneurysmal disease provides a safe and efficacious means of popliteal artery aneurysm repair with shorter hospitalization, lower wound complication rates, and excellent long-term patency compared to standard open technique.

Effect of Different Irrigation Patterns on Oat-Vetch Mixed Forage Production System in Rasuwa, Mid Hills of Nepal

Abstract: The scarcity of forage resources, particularly in Nepal's midhills, poses a challenge to the sustainable development of livestock production. In order to address issues, an experiment was carried out in 2020 at Kalika Municipality in Rasuwa District, Nepal, to determine the best forage combinations in terms of total dry matter productivity. With irrigation as a main plot effect, a 4*3 factorial RCB design was used with four replications. Crop species included oat (Avena sativa, Kamdhenu), common vetch (Vicia sativa), and combinations of oat and vetch within a sub plot. Irrigation treatments included none, once per month (30-day interval), twice per month (15-day interval), and three times per month (10-day interval). Temperature and precipitation data from nearby stations were taken from the Department of Hydrology and Meteorology. The first harvest was taken after 65 days of sowing (DAS), with consecutive harvests after 35 days of the initial harvest. The experimental findings revealed that the first, second, and total dry matter production were altogether found highest in the three times irrigated plot (2.47±0.25, 1.38±0.21, 3.85±0.46 respectively) and lowest in the rainfed condition (1.37±0.22, 0.69±0.12, 2.07±0.33 ton/ha respectively) with statistically highly significant result (p<0.001). The oat and vetch mixed cropping pattern had statistically higher dry matter production in the first (2.66 0.14 ton/ha), second (1.5 0.13 ton/ha), and overall average total production of (4.16 0.25 ton/ha), among the subplot effect (species). Additionally, among the subplot effects, the oat and vetch mixed cropping had the highest dry matter production in terms of first harvest yield, regrowth, and overall yield (p<0.01). Oat sole cropping could be replaced with mixed cropping of oat and vetch at a ratio of 50:50 (50:10 kg ha-1) because it produced the highest yield advantage, including forage quality. These findings provide scientific support for common vetch-oat intercropping as a sustainable approach to increase forage production with 10-day irrigation interval. These mixtures appear promising for the development of sustainable crop production with low external input and higher economic yield, and they can be used as a viable option by farmers in rainfed mid-hills of Nepal

Evaluation of harvest yield and beverage quality of coffee under ethylene application

The coffee plant is characterized by the irregular ripening of its fruits. This uneven ripening often makes it impossible to optimize its harvest, since green fruits are more adhered to the plant than those in the ripe and overripe stages. In addition, it can influence the final product’s beverage quality. The use of ethylene is an alternative to optimize and increase the harvest yield of coffee, besides reducing expenditures on labor and post-harvest ground picking. This study was carried out to examine the harvest yield of coffee variety Mundo Novo IAC 379/19 under different ethylene rates as well as to analyze beverage quality in the different treatments. The experiment was laid out in a randomized-block design with four treatments (ethylene rates: 0, 300, 500, or 700 mL ha-1). The plots consisted of nine plants and three replications, but only the three central plants were evaluated. Results were analyzed by Tukey’s test at a significance level of 5%. The rates of 700 and 300 mL ha-1 provided the lowest amount of green fruits, whereas the percentage of ripe fruits was equivalent between treatments. The treatment with 700 mL ha-1 resulted in the highest percentage of fruits in the overripe stage, among the evaluated rates. Ethylene use did not increase harvest efficiency. Control treatment provided a significantly higher number of green fruits. Additionally, the use of ethylene-induced changes in the chemical composition of the bean and beverage quality.

Multitrait Pseudomonas sp. isolated from the rhizosphere of Bergenia ciliata acts as a growth-promoting bioinoculant for plants

Multifunctional plant growth-promoting bioinoculants are used to enhance growth, harvest yields, and add economic value to agricultural crops. In this study, such bioinoculant, BC-II-20 (Pseudomonas sp.), was isolated from the rhizospheric soil of a medicinal plant Bergenia ciliata from the Garhwal Himalayas, Uttarakhand, India. After characterization, supplementation with Pseudomonas sp. was used to study growth stimulation in a commercially important medicinal plant, Andrographis paniculata (Kalmegh), and it depicted enhanced physiological growth parameters under controlled conditions. Bacterial seed priming and also supplementation led to early and increased germination and plants displayed better vegetative growth during the entire growth stages. Early initiation of flowers and the appearance of pods occurred in inoculated plants, ultimately leading to the reduction in the life cycle of the plant. At the time of harvesting, there was an increase in the physiological parameters such as shoot length (38%), root length (14%), fresh weight (57%), dry weight (60%), number of panicles, and root branching. Photosynthetic efficiency was also higher, and ultimately, overall plant growth was improved by bacterial inoculation. The eco-friendly and sustainable use of this bioinoculant will provide an alternative to harmful chemical fertilizers and has become increasingly important. In conclusion, we reported a promising bioinoculant having plant growth-promoting traits, which promotes growth and development in A. paniculata and may be applied to other plants also.

Macronutrient omission influences morphological parameters, growth, and yield in Arracacia xanthorrhiza Bancroft

Mineral nutrition in arracacha is a critical production factor that conditions harvest yield. Few studies have been developed in nutrition and physiology, this does not allow to the design of ideal fertilization programs; consequences are increased production costs, soil degradation, and low-quality storage roots. Therefore, this study aimed to characterize the symptoms associated with macronutrient deficiency in arracacha plants and its effect on morphological parameters, the accumulation of fresh and dry biomass, and the distribution of dry matter in the different organs. Under greenhouse conditions, the experiment was conducted in Cajamarca, Tolima, Colombia. A completely randomized design was implemented, with seven treatments and six replicates (6 solutions lacking N, P, K, Ca, Mg, and S and Hoagland complete solution). Forty-two seedlings were transplanted, to which the complete solution was applied for 75 days, increasing the concentrations from 0.25 M to 1 M, and then nutritional deficiencies were induced. Deficiencies caused by macronutrients in arracacha plants exhibited visual symptoms and changes in their morphology. The omission of N, Ca, and S generated the most severe symptoms, drastically affecting plant height, leaf width, number of leaves, and plant mass accumulation. In the case of P, leaves became small and intense green with a violet margin. The Mg and K generated leaves with interveinal and margin chlorosis. Plants with the omission of macronutrients allocated dry mass in the following order: stem, storage roots, propagules, and leaves.

Near-infrared spectroscopy for rapid evaluation of winter cereals and Italian ryegrass forage mixtures.

Near-infrared (NIR) spectroscopy was employed to determine the differences between forage mixtures of winter cereals and Italian ryegrass and to evaluate fermentation characteristics of mixed silages. Forages were harvested on five phases (Cuts 1-5), with 1 week interval (n = 100). The yield of the last harvest (Cut 5) was ensiled and analyzed on four different days (D0, D7, D14, and D90) (n = 80). Principal component analysis based on the NIR data revealed differences according to the days of harvest, differences between winter cereals and Italian ryegrass forages, and differences in the fermentation stages of silages. The partial least square regression models for crude protein (CP), crude fiber (CF), and ash gave excellent determination coefficient in cross-validation (R2 CV > 0.9), while models for ether extract (EE) and total sugar content were weaker (R2 CV = 0.87 and 0.74, respectively). The values of root mean square error of cross-validation were 0.59, 0.76, 0.22, 0.31, and 2.36 %DM, for CP, CF, EE, ash, and total sugar, respectively. NIR proved to be an efficient tool in evaluating type and growth differences of the winter cereals and Italian ryegrass forage mixtures and the quality changes that occur during ensiling.

Differences in Vegetative and Generative Characters of M2 Generation of Mutant Rice Compared to Wild Types and Commercial Cultivars

This study aims to obtain information on the differences in vegetative and generative characters of M2 generation rice mutants compared to wild types (MSP13 line) and commercial cultivars (IR64 and Ciherang). Gamma ray radiation treatment at 200 Gy was carried out on MSP13 line rice seeds in the M0 generation. The observation variables included plant height, number of productive tillers, age at harvest, weight of well-laden grains, and weight of 100 grains. The data obtained were analyzed by t test and cluster analysis. The results of t test showed that there are three M2 generation of mutant rice plants that have shorter plant sizes (dwarf), potential number of productive tillers, early harvest period and yield, compared to the wild type (MSP13 line), Ciherang and IR64 cultivars. Cluster analysis based on vegetative, generative and yield characters, obtained groups consisting of 9 and 66 rice mutant individuals with 21.87 % and 21.11 % similarity respectively compared to other rice mutant groups as well as wild type, Ciherang and IR64 varieties.

Assessment of combining ability comprising alc, nor and rin mutant alleles of tomato under main and late planting seasons

Seventy four genotypes of the tomato (14 lines, four testers of ripening mutant and their 56 F1 crosses developed in line ? tester mating fashion) were appraised under main (E1) and late (E2) planting season at Department of Vegetable Science, Punjab Agricultural University, Ludhiana, Punjab, India. To find out few general and specific combiners, if some, which might be utilized in furthermore breeding programmes to prolong the fruit harvesting span of tomato in the Punjab conditions. The findings hinted in general, the particular parent or hybrid could not be used to assess all examined characters with same efficiency. In main (E1) season line, FL-556 was found best general combiner for average fruit weight, locules number, pericarp thickness, P/E ratio, dry matter and lycopene content; PAU 114 for average fruit weight, lesser locules, pericarp thickness, TSS and dry matter. During late (E2) planting season line, Punjab Ratta found with good GCA values for average fruit weight, lesser locules number, pericarp thickness and TSS content; Roma for average fruit weight, locules number, pericarp thickness and P/E ratio. Similarly tester, alc-IIHR-2050 for pollen viability, minimum days from transplanting to first harvest, harvesting span, average fruit weight, pericarp thickness and P/E ratio in main (E1) season while, for pollen viability, average fruit weight, pericarp thickness and P/E ratio in late (E2) season. The received results furthermore illustrated the best combinations that possessed significant values of SCA which effectively combine to develop a cross with good performance. In main (E1) season from combinations, F1 hybrid SMZ-867 ? rin-Rutgers were registered with best specific combiner for pollen viability, average fruit weight, lesser locules number, Pericarp thickness and P/E ratio; PAU 2381 ? nor-RM-1 for harvesting span, average fruit weight, pericarp thickness, total fruit yield and lycopene content. Likewise, in late (E2) season cross, SMZ-867 ? nor-RM-1 for pollen viability, minimum days from transplanting to first harvest, harvesting span and fruit yield; LT-44 ? alc-IIHR-2050 for pollen viability, average fruit weight, lesser locules and pericarp thickness.

Cluster microclimate, canopy management and its influence on the berry (size and composition) quality

Sunlight and microclimate inside the clusters’ zone are key factors in berry development and must composition. Plant geometry and training system should be joined with a proper sunlight and temperature cluster microclimate and, also in the rest of the plant. Berry temperature can vary between 2 and 10 ºC or even more in inner clusters, depending on their exposure (Spayd et al., 2002). Sunlight, air ventilation within the canopy, temperature cluster and microclimate are affected by the exposure and radiation percentage received by grapes during its growth and maturation period (Deloire and Hunter 2005). In Mediterranean conditions (warm and dry climate), the use of porous systems may help plants establish a better leaf distribution inside this area (de la Fuente et al., 2015), providing more space and enhancing certain physiological processes, both in leaves (photosynthesis, ventilation, transpiration) and berries (growth and maturation). Grapes exposed to direct radiation are more sensitive to ripening and they can even suffer a dehydration process in the Mediterranean regions, where the temperature during the ripening after midday is frequently between 30-35 ºC or higher than 40 ºC (de la Fuente et al., 2015). A key point for well microclimate management inside the canopy is heat flux control, which is usually generated by three factors: surface area (SA) to PAR (direct or indirect) radiation; intensity or thermal value (related to the temperature) and time of exposure (de la Fuente, 2009; de la Fuente et al., 2013). Sprawl systems are non-positioned systems where vegetation is in multidirectional directions. Therefore, as sun position changes along the day, some leaves are first shaded and then others, so the sun leaf exposure decreases (Gutiérrez et al., 2021). The study was conducted in D.O. Uclés vineyards (lat. 39º50’8” N; long. 3º09’48.6” W; elevation 746 m above sea level) during the 2020 season, in cv. Tempranillo. The trial was designed with two training system: Vertical Shoot Positioned (VSP) and Sprawl (SP). Berry sampling was done every three days within the final 15 days before the estimated harvest date. A single sample comprised 100 berries collected from the clusters of the 10 selected vines in each block. Weight, size, must composition (reducing sugar, pH, acidity, volatile acidity, etc.) and skin composition (total and acylated monomeric pigments, TPI) were analysed. Regarding the berry composition, SP accumulated larger concentration of reducing sugars (+7.4%). No statistical differences were observed in the remaining oenological parameters measured in the berries between treatments. Nevertheless, inside total pigments and color parameters, TPI values reached significantly higher (+40%) in the SP vs VSP treatments. In the total concentration of pigments (including the acylated fraction) and pH, no differences were founded. Berry's weight and size showed some relevant differences between treatments. During the end maturity-harvest period, the berry weight (12-11%) and berry size (6-9%) were higher in SP treatment compared to VSP. These results suggest that the SP systems can induce an increment of reducing sugars, and TPI and also, can modulate the berry weight and size, helping to control overripening and berry dehydration processes. Therefore, sprawl systems (SP) represent an alternative to VSP systems in warm areas for achieving an increment of pigments, as well as for better control of the accumulation of reducing sugars, without compromising the harvest yield (higher berry weight and size).

Maximizing Harvest Yields in a Three-Species System

Maximizing Harvest Yields in a Three-Species System

Evolutionary bifurcation diagrams of A <inline-formula><tex-math id="M1">$ P $</tex-math></inline-formula>-Laplacian generalized logistic problem with nonnegative constant yield harvesting

We study evolutionary bifurcation diagrams for the $ p $-Laplacian generalized logistic problem \begin{document}$ \left \{ \begin{array} [c]{l} \left( \varphi _{p}(u^{\prime }(x))\right) ^{\prime }+\lambda h(u)-k(u)-\mu = 0, \;\;-1<x<1, \\ u(-1) = u(1) = 0, \end{array} \right. $\end{document} where $ p>1, $ $ \lambda >0 $ is a bifurcation parameter and $ \mu \geq 0 $ is the harvesting parameter. We assume that $ h, k $ satisfy $ h(0) = k(0) = 0 $, $ h(u), k(u)>0 $ on $ (0, \infty ), $ and $ h, k $ satisfy certain hypotheses such that, for each $ \lambda >0 $, $ g_{\lambda }(u): = h(u)-\frac{k(u)}{\lambda } $ is positive and strictly $ p $-concave on $ (0, \zeta _{\lambda }) $, where $ \zeta _{\lambda } $ is the unique positive zero of $ g_{\lambda }(u) $. We mainly prove that, for fixed $ \mu >0 $, on the $ (\lambda , \left \Vert u\right \Vert _{\infty }) $-plane, the bifurcation diagram always consists of a $ \subset $-shaped curve and then we study the structures and evolution of bifurcation diagrams for varying $ \mu >0 $. We give two interesting applications.