Analysis of Plant Growth and Yield in Varieties of Tomato (Solanum lycopersicum L.) Grafted onto Different Eggplant Rootstocks

This study aimed to examine plant growth of tomato grafted onto different eggplant rootstocks. We applied a randomized block design comprising twelve treatments with three replicates. Three varieties of tomato—Cervo, Karina, and Timoty—and three rootstocks—Gelatik, EG203 line, and Solanum torvum—were selected for this study. Nongrafted tomato plants of the same varieties were used as controls. The variables recorded were the number of branches, the diameter of scions and rootstocks, root length, and root dry weight at 4, 6, 8, and 10 weeks after planting (WAT) and relative growth rate, specific leaf area, and net assimilation rate at 4, 8, and 12 WAT. Grafted tomato plants demonstrated better growth than controls. There was a significant relationship between yield, plant growth parameters, and photosynthetic organs, expressed by higher production, greater scion diameter, longer roots, and increased relative growth rate, leaf area ratio, and net assimilation rate of grafted plants, compared to the controls.

Effects of Mechanically Transplanting Methods and Planting Densities on Yield and Quality of Nanjing 2728 under Rice-Crayfish Continuous Production System

Rice–crayfish continuous production system offers high economic and ecology benefits, which developed rapidly in China. To investigate the effects of different mechanical transplanting methods and planting densities on rice yield and quality, Nanjing 2728 was used to determine rice growth performance under mechanically transplanted carpet seedling (MTCS) with equal row spacing (30 cm) at five spacings and mechanically transplanted pot seedling (MTPS) with wide and narrow rows (23 + 33 cm) at five spacings. The results showed that MTPS presented significantly higher rice yields than MTCS as more spikelets per panicle. Rice yields of both mechanical transplanting methods first increased and then reduced with decreasing planting density, and its highest value was obtained at 77.9 × 104 seedlings ha−1. Compared with MTCS at the same stage, rice tiller dynamics of MTPS first increased and then decreased. Additionally, its dry matter accumulation per stem at jointing, heading, and maturity stages, leaf area index, photosynthetic potential, crop growth rate, and net assimilation rate were all significantly higher relative to MTCS. For each mechanical transplanting method, dry matter accumulation per panicle, leaf area index, photosynthetic potential, crop growth rate, and net assimilation rate from the sowing to jointing stages declined with decreasing planting density, while dry matter accumulation per stem and net assimilation rate from the heading to maturity stages increased. Compared with MTCS, MTPS significantly improved rice milling and appearance quality, decreasing density was also beneficial to rice milling and appearance quality, while grain content of amylose and protein were not sensitive to both transplanting method and planting density. Consequently, MTPS with 13.8 cm plant spacing is a suitable mechanical transplanting method for Nanjing 2728 to obtain better yield and quality under rice–crayfish continuous production system.

The responses of photosynthesis, fruit yield and quality of mini-cucumber to LED-interlighting and grafting

ABSTRACT Supplemental lighting is becoming a common practice for horticultural greenhouse industries, especially at high-latitude countries. However, no scientific reports were found on this topic in tropical climate countries. This study investigates the effects of LED-interlighting and grafting on photosynthetic response and yield and quality of mini cucumber (hybrid Larino). The experiment took place from April to August in a greenhouse located at a Cwa climate type in Piracicaba (SP), Brazil (22°42’S; 47°37’W; 541 m altitude). The experiment was arranged in completely randomized block design composed of three types of seedlings (ungrafted hybrid, hybrid grafted onto rootstock cultivar Keeper and hybrid grafted onto rootstock cultivar Shelper) and two environments related to light condition (LED supplemental light and natural light as control). The LED devices were placed horizontally at 15 cm from the plants and at 1,5 m height from the floor. The LEDs emitted a photon flux of 220 µmol m-2 s-1 by red light (80%) with a peak wavelength of 662 nm and blue light (20%) with a peak wavelength of 452 nm. Lighting was used for 12 h d-1 from 30 days after seedling transplanting until the end of the growth period. The air temperature and relative humidity (RH) were maintained at 23.5±4°C and 72±10% during the light period, respectively. At night, average temperature was 18.6±5°C and the RH was 90±5%. The LED-interlighting treatment increased in 40% the plant CO2 net assimilation rate compared to plants grown under natural light in the greenhouse. Plants grafted onto both rootstocks had higher CO2 net assimilation rate (µmol CO2 m-2 s-1), apparent carboxylation efficiency (µmol CO2 mol air-1) and apparent electron transport rate (µmol electrons m-2 s-1) than non-grafted ones. The early yield increased 11.6% and 24% in response to LED-interlighting and grafting, respectively. The commercial yield also increased with LED light at rate of 13% but did not enhance with grafting. Postharvest quality parameters as titratable acidity, total soluble solids and shelf life were not affected by the LED light supplementation. Our study shows that even in tropical climate conditions LED-interlighting can be used as a tool to improve commercial cucumber production.

Growth of canola hybrids resistant and sensitive to herbicides

Plant growth analysis is useful for determining adequate management practices and exploring the maximum yield potential of cultivars or hybrids. Canola hybrids with resistance to herbicides have been studied and registered for Brazilian conditions, as they improve weed management in canola crops. This study evaluated the growth of canola hybrids resistant to triazine or imidazolinone herbicides compared to a sensitive hybrid. The experiment was conducted using a completely randomized design, with four replications, in a bifactorial scheme using three hybrids and six sampling times. The canola hybrids used were Hyola 571CL (resistant to imidazolinones), Hyola 555TT (resistant to triazines), and Hyola 61 (sensitive to both herbicides). Height, leaf area, and dry matter of roots, leaves, stems, and shoots of the plants were evaluated at 14, 28, 42, 56, 70, and 119 days after emergence (DAE). The physiological indices absolute growth rate, leaf area ratio, specific leaf area, and net assimilation rate were calculated, and yield indices evaluated. Compared to Hyola 61, the Hyola 555TT hybrid showed lower values of leaf dry matter at 70 DAE, absolute growth rate up to 56 DAE, and net assimilation rate at 14 and 28 DAE, and a higher leaf area ratio at 56 DAE, whereas the hybrid Hyola 571CL presented lower leaf area and lower leaf dry matter at 70 DAE. At flowering, compared to Hyola 61, the hybrid Hyola 571CL presents lower leaf area, and the hybrids Hyola 555TT and Hyola 571CL have lower leaf dry matter accumulation. Differences in the growth of canola hybrids Hyola 555TT, Hyola 571CL and Hyola 61 do not cause differences in their grain yield.

Functional growth analysis of diploid potato cultivars (Solanum phureja Juz. et Buk.)

Plant growth analysis has been widely used to study factors that influence plant growth. This analysis uses a set of quantitative methods that describe and analyze the growth of plants and their organs. It uses data from direct measurements (weight, area, volume) and quantifies and analyzes growth using indexes based on models defined by mathematical functions. This study conducted a functional growth analysis of diploid potato cultivars in Colombia. The functional growth analysis of diploid potato cultivars was carried out over three consecutive growing seasons in Medellín, Colombia. A randomized block design was used with two levels of fertilization and five repetitions. The first factor corresponded to the three potato cultivars, and the second factor was two fertilization levels: 260 and 778 kg of fertilizer per hectare. Samples were taken weekly, and each sample was an entire plant per experiment unit. The dry weight of each organ and the leaf area were measured. These measurements were used to calculate the relative growth rate, leaf area ratio, net assimilation rate, and specific leaf area. The development time was evaluated in accumulated degree-days with threshold temperatures of 2 and 29°C. The three cultivars recorded their highest net assimilation rate at 1,252 accumulated degree days (ADD), with values of 0.0002565, 0.0002021, and 0.0001778 g cm-2 ADD-1 in the ‘Latina’, ‘Guaneña’, and ‘Colombia’ cultivars, respectively. The Latina cultivar stood out in several physiological characteristics, including the fastest developing cultivar. ‘Latina’ also had the highest total dry mass accumulated in the cycle (271.05 g) and accumulated dry matter in tubers (237 g).

Net Assimilation Rate and Agronomic Efficiency of Nitrogen in Tartago (Ricinus communis L.) (Euphorbiaceae) in Dry Climate

To know the dynamics of net assimilation rate and the agronomic efficiency of nitrogen in the Tartago crop, seeds of three accessions were collected in Teotitlán de Flores Magón, Oaxaca, Mexico. The treatments consisted of nitrogen fertilization of 0, 20, 40, 60, 80, 100, 120, and 140 kg (N) ha−1, evaluated under a completely randomized design. The experimental unit was constituted by a Tartago plant inside of a polyethylene bag with soil of the zone, and four repetitions were considered. The response variables were dry biomass, number of fruits per plant, agronomic yield, harvest index, nitrogen agronomic efficiency, SPAD units, and net assimilation rate. The results indicate that climatic conditions did not influence the growth and development of the crop. The maximum values for all of response variables were achieved with the application of nitrogen in a range of 60 to 140 kg ha−1. The net assimilation rate was adjusted to a quadratic model. It is concluded that the Tartago responds positively to the application of nitrogen and can be an alternative to be grown in dry climate.

Photosynthetic and Production of Urochloa ruziziensis Inoculated with Azospirillum brasilense under Drought

Aims: The objective of this study was to evaluate the photosynthetic activity and production of Urochloa ruziziensis when inoculated with Azospirillum brasilense in the presence and absence of drought. Study Design: Randomized block design and factorial 2x2. Methodology: The first factor was the presence or absence of seed inoculation with A. brasilense strains AbV5 + AbV6; the second factor was the presence or absence of drought. The variables evaluated were: relative water content (RWC), soil gravimetric moisture, net assimilation rate of CO2, response in function of active photon flux density, apparent quantum efficiency, light compensation point, absolute integrity of membrane, damage to membranes, dry mass aborted leaves, and total dry mass of aerial part. Results: Results demonstrate that plants maintained in drought presented a reduction in all evaluated variables. Under conditions of drought the use of A. brasilense promoted smaller variations in RWC, net assimilation rate of CO2, apparent quantum efficiency, light compensation point, absolute integrity of membrane, and damage to membranes; no variations were observed for dry mass, aborted leaves or total dry mass of aerial part. Conclusion: The inoculation of U. ruziziensis seeds with A. brasilense mitigates drought damage in plant physiology, but it does not mitigate leaf losses or plant productivity.

Pertumbuhan, Produksi dan Kandungan Nutrisi Hijauan Unggul pada Tingkat Naungan yang Berbeda

ABSTRAK. Penelitian bertujuan untuk mendapatkan spesies hijauan pakan unggul yang toleran terhadap naungan agar dapat dikembangkan pada lahan perkebunan kelapa sawit. Penelitian dilaksanakan di kebun percobaan Gowa Balai Pengkajian Teknologi Pertanian (BPTP) Balitbangtan Sulawesi Selatan. Penelitian menggunakan 5 spesies hijauan unggul yaitu Brachiaria hybrid cv. Mulato, Paspalum atratum, Setaria sphacelata, Brachiaria brizantha, dan Panicum maximum pada tiga tingkat naungan yaitu 0%, 50% dan 65%. Setiap spesies hijauan ditanam di bawah naungan berukuran 2 x 1,5 m2 dengan tiga ulangan dalam rancangan petak terbagi. Peubah yang diukur yaitu laju pertumbuhan relatif, luas daun spesifik, laju asimilasi bersih, produksi kumulatif, dan kandungan nutrisi (protein, NDF dan ADF). Hasil yang diperoleh menunjukkan bahwa Brachiaria hybrid cv. Mulato dan Panicum maximum memiliki laju pertumbuhan relatif yang lebih tinggi pada berbagai tingkat naungan dan nilai laju asimilasi bersih tinggi meskipun ternaungi hingga 65%, namun nilai rata-rata luas daun spesifik (LDS) paling rendah dibanding hijauan lainnya. Simpulan spesies Brachiaria hybrid cv. Mulato merupakan hijauan unggul yang paling toleran terhadap naungan dibanding keempat spesies hijauan lainnya. (Growth, production, and content of superior forage nutrients at different shade levels) ABSTRACT The research aimed to obtain superior` forage species that are tolerant to shade so they can be developed on oil palm plantations. The research was carried out in the Gowa experimental garden of the Balai Pengkajian Teknologi Pertanian (BPPT) South Sulawesi. This study used 5 superior forage species namely Brachiaria hybrid cv. Mulato, Paspalum atratum, Setaria sphacelata, Brachiaria brizantha, Panicum maximum and three shading levels of 0%, 50% and 65%. Each forage species is planted in a 2 x 1.5 m2 shade with three replications in a divided plot design. The variables measured are relative growth rates, specific leaf area, net assimilation rate, cumulative production, and nutrient content (protein, NDF and ADF). The results obtained showed that Brachiaria hybrid cv. Mulato and Panicum maximum have a higher relative growth rate at various shade levels and the value of the net assimilation rate is high even though it is shaded by 65%, but the average specific leaf area value is the lowest compared to other forages. The conclusion is Brachiaria hybrid species. Mulato is a superior forage that is most tolerant to shade compared to the other four forage species.

WATER DEFICIT AFFECTS GAS EXCHANGE IN PEACH TREES CULTIVAR CHIMARRITA GRAFTED ONTO DIFFERENT ROOTSTOCKS

WATER DEFICIT AFFECTS GAS EXCHANGE IN PEACH TREES CULTIVAR CHIMARRITA GRAFTED ONTO DIFFERENT ROOTSTOCKS LETICIA NEUTZLING RICKES, ELSA KUHN KLUMB, CARLOS DAVI SANTOS E SILVA, MARCOS ANTONIO BACARIN, VALMOR JOÃO BIANCHI 1 Dr.(a) em Fisiologia Vegetal pela Universidade Federal de Pelotas, Instituto de Biologia, Departamento de Botânica, Campus Universitário, Capão do Leão, RS – Brasil, E-mail: [email protected], [email protected] 2 Mestra em Fisiologia Vegetal pela Universidade Federal de Pelotas, Instituto de Biologia, Departamento de Botânica, Campus Universitário, Capão do Leão, RS – Brasil, E-mail: [email protected] 3 Prof. Dr. Universidade Federal de Pelotas, Instituto de Biologia, Departamento de Botânica, Campus Universitário, Capão do Leão, RS – Brasil, E-mail: [email protected], [email protected] 1 ABSTRACT The aim was to investigate the effect of the water deficit on the gas exchange of Chimarrita plants grafted onto five different rootstocks (Tsukuba 1, Tsukuba 2, Tsukuba 3, Aldrighi 1, and Selection UFPel 0402), i.e., five combinations ‘Chimarrita’/rootstocks. The factorial scheme consisted of two water conditions (control and water deficit) and eight days of evaluation (0, 1st, 2nd, 3rd, 4th, 6th, 7th, and 9th, the latter two were the recovery period). Gas exchange was assessed with the aid of the portable CO2 infrared analyzer. Results were subjected to the analysis of variance (p≤0.05) by using Tukey’s test in order to compare the means between treatments at each day of stress for each ‘Chimarrita’/rootstocks combination. It was found that the different ‘Chimarrita’/rootstocks combinations showed a distinct physiological behavior regarding the initial water-deficit tolerance. Plants consisting of the combination ‘Chimarrita/Aldrighi 1’ had the highest initial water-deficit tolerance. The reduction in the net assimilation rate in face of the water deficit is not only related to the stomatal limitation, suggesting that there may also be non-stomatal limitations. Seventy-two hours after providing irrigation back to plants, all combinations evaluated showed an overall resilience of the physiological performance. Keywords: Prunus persica, abiotic stress, stomatal conductance, net assimilation rate. RICKES, L. N.; KLUMB, E. K.; SILVA, C. D. S. e; BACARIN, M. A.; BIANCHI, V. J.DÉFICIT HÍDRICO AFETA AS TROCAS GASOSAS EM PESSEGUEIRO CULTIVAR CHIMARRITA ENXERTADA SOBRE DIFERENTES PORTAENXERTOS 2 RESUMO O objetivo foi avaliar o efeito do déficit hídrico sobre as trocas gasosas em plantas da cultivar Chimarrita enxertada sobre cinco diferentes portaenxertos (Tsukuba 1, Tsukuba 2, Tsukuba 3, Aldrighi 1 e Seleção UFPel 0402), ou seja, cinco combinações ‘Chimarrita’/portaenxertos. O esquema fatorial foi composto de duas condições hídricas (controle e déficit hídrico) e oito dias de avaliação (0, 1º, 2º, 3º, 4º, 6º, 7º e 9º, os dois últimos sendo período de recuperação). As trocas gasosas foram avaliadas com um analisador portátil a infravermelho de CO2. Os resultados foram submetidos a análise de variância (p≤0,05), utilizando-se o teste de Tukey para comparação de médias entre os tratamentos em cada dia de estresse de cada combinação ‘Chimarrita’/portaenxertos. Verificou-se que as diferentes combinações de ‘Chimarrita’/portaenxertos apresentaram comportamento fisiológico diferencial para a tolerância inicial ao déficit hídrico. Plantas compostas pelas combinações de enxertia entre ‘Chimarrita’/Adrighi 1’ foram as que apresentaram a maior tolerância inicial ao déficit hídrico. A redução da taxa assimilatória líquida perante o déficit hídrico, não está relacionada principalmente à limitação estomática, sugerindo-se que ocorrem também limitações não estomáticas. Após 72h do retorno da irrigação das plantas, todas as combinações avaliadas demonstraram total capacidade de recuperação do desempenho fisiológico. Palavras-chave: Prunus persica, estresse abiótico, condutância estomática, taxa assimilatória líquida.