Search Results (5)

To better understand the growth adaptability of various maize varieties to the climate of the Alar region in Southern Xinjiang Province, an experiment was conducted using seven distinct maize varieties as test materials. A one-way randomized block design was applied to both experimental groups. In 2021 and 2022, a total of 19 indicators were observed for comparative analysis, including antioxidant enzyme activities and agronomic traits. Principal component analysis and cluster analysis were used to evaluate the adaptability of the maize varieties. The findings revealed that: (1) All seven maize varieties exhibited robust growth, with notable differences in their respective trait profiles. Specifically, the yield traits of Jin’ai 588 and Denghai 3672 showed relatively consistent performance over the two-year period. (2) Five principal components (100-kernel weight, bald tip length, catalase (CAT), number of leaves, and angle of leaf pinch at the ear) were extracted from the 19 traits via principal component analysis, with a cumulative contribution rate of 84.689%. This represented the majority of the information regarding the seven maize varieties. After calculating the comprehensive index F value, the results indicated that Xinyu 66 and Denghai 3672 had high composite scores, suggesting high production potential and suitability for cultivation in this region. Conversely, Xinyu 24 showed the lowest composite score, indicating that it is not suitable for planting in this area. (3) Ultimately, the seven maize varieties were categorized into three groups through cluster analysis; this is the same as the result of principal component analysis. This classification provides a reference for the promotion and utilization of different varieties in the southern border region and aims to optimize the comprehensive trait selection of the varieties studied. Full article

Nursery material intended for establishing intensive apple orchards should be characterised by a dominant and straight leader with an appropriate number of shoots that develop at the right height and are regularly spaced along the leader. The use of well-branched trees can lead to fruiting in the first year after planting. However, many apple varieties have difficulty forming lateral shoots due to strong apical dominance. The aim of the study was to assess the effectiveness of treatments stimulating the branching of maiden apple trees of the ‘Gloster’ variety. The research was carried out in 2017–2019 at a private nursery farm located in eastern Poland. The studied trees were subjected to a mechanical branching stimulation treatment, which consisted of pinching off 4–5 of the youngest leaves located below the growth cone, and chemical branching stimulation treatments, which consisted of applying growth regulator mixtures in the form of an aqueous solution, i.e., BA+GA₃ and BA+GA₄₊₇. The conducted studies showed that the type of branching-stimulating treatment had a significant effect on the height and trunk diameter of the maiden trees, the number of lateral shoots, the average length of one shoot and the sum of the lengths of all sylleptic shoots. The maiden trees treated with BA+GA₃ were characterised by the best quality among the analysed combinations. Maiden apple trees treated with BA+GA₃ were the tallest (2017—167.7 cm; 2018—175.3 cm; 2019—164.4 cm), produced the largest number of shoots (2017—6.5 pcs; 2018—6.8 pcs; 2019—6.3 pcs) and had the largest sum of lateral shoot lengths (2017—148.0 cm; 2018—155.4 cm; 2019—140.6 cm) among the evaluated combinations. The number of treatments and the concentration of applied growth regulators had a significant effect on the structure of the crown of the maiden apple trees of the ‘Gloster’ cultivar. Full article

In soybean, lodging is sometimes caused by strong winds and rains, resulting in a decrease in yield and quality. Technical measures against lodging include “pinching”, in which the main stem is pruned when excessive growth is expected. However, there can be a decrease in yield when pinching is undertaken when the risk of lodging is relatively low. Therefore, it is important that pinching is performed after the future risk of lodging has been determined. The lodging angle at the full maturity stage (R8) can be explained using a multiple regression model with main stem elongation from the sixth leaf stage (V6) to the blooming stage (R1) and main stem length at the full seed stage (R6) as the explanatory variables. The objective of this study was to develop an areal lodging prediction method by combining a main stem elongation model with areal main stem length estimation using UAV remote sensing. The main stem elongation model from emergence to R1 was a logistic regression formula with the temperature and daylight hours functions f (T_i, D_i) as the explanatory variables. The main stem elongation model from R1 to the peak main stem length was a linear regression formula with the main stem length of R1 as the explanatory variable. The model that synthesized these two regression formulas were used as the main stem elongation model from emergence to R8. The accuracy of the main stem elongation model was tested on the test data, and the average RMSE was 5.3. For the areal main stem length estimation by UAV remote sensing, we proposed a soil-adjusted vegetation index (SAVI_vc) that takes vegetation cover into account. SAVI_vc was more accurate in estimating the main stem length than the previously reported vegetation index (R² = 0.78, p < 0.001). The main stem length estimated by the main stem elongation model combined with SAVI_vc was substituted into a multiple regression model of lodging angle to test the accuracy of the areal lodging prediction method. The method was able to predict lodging angles with an accuracy of RMSE = 8.8. These results suggest that the risk of lodging can be estimated in an areal manner prior to pinching, even though the actual occurrence is affected by wind. Full article

Cucumber (Cucumis sativus L., cv. “Nina Z”) plants grafted onto squash (Cucurbita maxima, cv. “Yu Yu Ikki”) were grown in a greenhouse using the newly developed nutrient film technique (NFT) hydroponic system “Kappa land” (Mitsubishi aqua solutions Co., Ltd., Tokyo, Japan), from February to June 2022. The growth and development of cucumbers were examined under two different training methods: Lowering training (LT) and Pinching training (PT). Data collected were related to water and nutrient consumption, plant growth and development parameters, and the workload of the main activities. The results showed that plants grown under the LT recorded significantly higher total stem length (10.9 m) and number of nodes (133). In addition, from 21 April to 19 May, the leaf area index was significantly higher in the LT treatment. The highest total yield (15.4 kg m⁻²) and marketable yield per unit area (13.8 kg m⁻²) were recorded in the LT treatment. Regarding fruit growth, the fruits took 14 and 19 days to reach the standard harvest weight in the PT and LT treatments, respectively. In addition, the fruits were more straight in the PT treatment. The water use efficiency was not significantly different between the two treatments. However, the nutrient use efficiency was significantly higher in the PT treatment because plants produced more vegetative organs in the LT treatment instead of fruits. The work for removing old leaves and harvesting fruits was simplified in the LT treatment. The LT method can be effective for the automation of old leaf removal and fruit picking by the robot in the future. Full article

To date, mechanized picking of famous tea (bud, one bud one leaf) causes a lot of damage. Manual picking results in high-quality tea but the process is inefficient. Therefore, in order to improve the quality of mechanically harvested tea buds, the study of bionic picking is beneficial to reduce the damage rate of mechanical picking. In this paper, the manual flexible picking process is studied, and a bionic bladeless mechanical picking mechanics model is developed. The relationship between the mechanical properties and structural deformation of tea stalks is obtained by microstructural observation and mechanical experimental analysis and determination of the bud bionic picking mechanics flow by combined loading tests is carried out. The results show that the key factor for low damage in tea picking is the precise flexible force applied to different parts of the shoot tip during pinching, upward, and picking. The biological force of tea stalks is closely related to the stalk diameter and maturity of stalk tissue development. The larger the xylem of the tea stalk, the stronger its resistance to bending, stretching, and deformation. The stalks at the tender end of the tea are more resilient than the lower stalks and will not break under the action of large angle bending. Additionally, the stalks at the shoot tip have significantly lower pull-off force than the stalks at other places. By simulating the manual picking process, the mechanical picking mechanical parameters were determined to be a clamping pressure of 340 kPa, bending force of 0.134 N, and pull-off force of 5.1 N. These findings help the design of low-damage pickers for famous tea and provide a reference for low-damage bionic picking of tea. Full article