Semi-arid Tropical Conditions Research Articles

An elucidation on productivity, energetics, and carbon footprint of different forage land-use systems in semi-arid tropics of Karnataka, India

Forages are rapid biomass-generating crops that often demand intensive management. They necessitate a clear understanding of energy flow and carbon (C) footprinting which in turn helps in optimization of production resources and environmental impact assessment. Therefore, a field experiment was conducted for five consecutive years (2019–2023) to ascertain eight forage crops’ productivity, energetics, and C footprint. The crops under the annual monoculture system were maize and cowpea. While, Napier, Guinea, Rhodes, Green panic, Anjan grass, and Signal grasses were under perennial monoculture system. The results revealed that, the Napier grass was superior in biological productivity by recording 28%–50% higher green fodder yield over other forages. The energy analysis indicated that the Guinea grass consumed the highest energy (61,719 MJ ha−1 Year−1) during production, while Napier grass showed the highest energy output (32,5991 MJ ha−1 Year−1). Further, Napier grass outperformed the rest in terms of energy use efficiency (5.49), energy productivity (2.39 kg MJ−1), net energy gain (266,641 MJ ha−1 Year−1), energy profitability (4.49), nutrient energy ratio (14.7), and human energy profitability (558). Similar to energy input, Guinea grass production showed the highest C input (970 kg-CE ha−1 Year−1). Whereas, highest C output was observed with Napier grass (56,694 kg-CE ha−1 Year−1) due to its substantial C gain (55,805 kg-CE ha−1), C-efficiency ratio (63.79), and C-stability index (0.98). Consequently, Napier grass can be adopted as a productive, energy profitable, and C-efficient forage crop in semi-arid tropical conditions.

Rootstock Effects on Fruit Yield and Quality of 'BRS Tainá' Seedless Table Grape in Semi-Arid Tropical Conditions.

In viticulture, choosing the most suitable rootstock for a specific scion cultivar is an efficient and cost-effective way to increase yield and enhance the physicochemical characteristics of the fruit. The objective of this study was to evaluate the agronomic performance of the 'BRS Tainá' grapevine on different rootstocks under the conditions of the Sub-Middle São Francisco Valley. The main experimental factor consisted of eight rootstocks (IAC 313, IAC 572, IAC 766, 101-14 MgT, Paulsen 1103, Ramsey, SO4, and Teleki 5C), arranged in randomized blocks with four replicates. The experiment was conducted over four production cycles, from 2021 to 2023, in a commercial crop area in Petrolina, PE, Brazil. There were significant effects of rootstocks for the yield and number of bunches per plant, as well as berry length and firmness. 'BRS Tainá' achieved the highest yield (22.2 kg per plant) when grafted onto the Paulsen 1103 rootstock, which was superior to the yield on 101-14 MgT, IAC 313, and IAC 572 rootstocks. The highest number of bunches (88) was obtained with 'BRS Tainá' grafted on Paulsen 1103, while the lowest number (63) was obtained on IAC 572; both these rootstocks were not significantly different from the other rootstocks. For all scion-rootstock combinations, the mean values for soluble solid (SS) content, titratable acidity (TA), and the SS/TA ratio were similar to those previously described for 'BRS Tainá', meeting the commercialization standard. The results for the yield and number of bunches per plant indicate the suitability of grafting 'BRS Tainá' on Paulsen 1103 under the semi-arid tropical conditions of the São Francisco Valley.

Recent Advances and Prospects for Dragon Fruit (Hylocereus spp.) Plant Propagation Techniques

Dragon fruit (Hylocereus spp.) is a recently introduced super fruit in India, gaining popularity both in rural and urban areas because of its attractive colour, delicious taste, and high nutritive and medicinal values. It is adaptable to humid as well as semi-arid tropical and subtropical conditions. The growing acceptance of this fruit along with its enormous medicinal and antioxidant properties has increased the demand for its cultivation followed by quality planting materials in the desired quantity. Propagation of Dragon fruit can be done by both micropropagation sexual via seeds and asexual methods via stem cuttings, grafting, and micropropagation. In this review, attempts have been made to cover various fruit propagation methods along with other related crop features about which there is relatively scanty information. The assessment also attempted to highlight the prospective propagation locations for dragon fruit, which calls for additional study to produce more information and advance crop propagation methods.

Supplementation of Moringa oleifera leaf concentrate pellets on nutrient utilization, antioxidant status, and reproductive performance of prolific ewes during extreme summer months in semi-arid tropical conditions.

A feeding trial was conducted for a period of 60 days during extreme summer months to observe the effect of supplementation of Moringa oleifera leaves containing concentrate pellets on nutrient utilization, antioxidant status, and reproductive performance in Avishaan ewes reared under semi-arid condition. Forty adult non-pregnant cyclic ewes (2-3 years, 31.8 ± 0.81 kg body weight) were selected and randomly allocated into 2 groups of 20 animals each, viz., G-I (control) and G-II (treatment). The ewes were grazed on natural pasture for 8 h, offered ad libitum Cenchrus ciliaris hay after grazing and concentrate pellets @ 300 g/animal/day. The ewes in G-I were offered conventional concentrate pellets, whereas G-II ewes were offered concentrate pellets containing 15% Moringa leaves. The mean temperature humidity index during the period of study was 27.5 ± 0.3 and 34.6 ± 0.4 at 0700 h and 1400 h, respectively, indicating severe heat stress. Nutrient intake and utilization were comparable between the two groups. The antioxidant status was higher in G-II ewes as the values of catalase, superoxide dismutase, and total antioxidant capacity were higher (P < 0.05) in G-II ewes compared to G-I. The conception rate was higher (100%) in G-II ewes than G-I ewes (70%). Multiple birth percentage was 77.8% in G-II ewes, and it was comparable with the herd average of Avishaan (74.7%). However, ewes in G-I group exhibited a marked decline in multiple birth percentage (28.6%) than the normal herd average. Hence, it can be concluded that inclusion of Moringa oleiferaleaves in feeding of prolific Avishaan ewes improved their antioxidant status resulting in optimum reproductive performance during stressful summer months.

Estratégias de fertilização para reduzir a formação de frutos estenoespermo-cárpicos de manga na região semiárida

Abstract The mango cultivation has shown considerable losses, due to the intense occurrence of physiological disorders in its fruits, and stenospermocarpy is the main disorder under tropical semiarid conditions. So, the experiment was carried out to evaluate the potential loss of yield of mango cv. Palmer by stenospermocarpy, its relation with the nutritional state of the plant and yield as a function of fertilization strategies. The study was conducted in two experimental areas in the Brazilian semiarid. There is evidence that the leaf contents of phosphorus (P), iron (Fe) and zinc (Zn) influenced the development of stenospermocarpy fruits, associated with high temperature and low relative humidity in the flowering period of the crop. The incidence of fruits affected by stenospermocarpy reaches 90%, with an estimated yield loss of 28.81 Mg ha-1 for the mango cv. Palmer.

Review on Various Regeneration Techniques in Dragon Fruit (Hylocereus spp.)

Dragon fruit (Hylocereus spp.) is a recently introduced super fruit in India, gaining popularity both in the rural and urban areas because of its attractive colour, delicious taste, high nutritive and medicinal values. It is adaptable to humid as well as semi-arid tropical and subtropical conditions. The growing acceptability of the fruit along with its immense antioxidants and medicinal properties has led to high demand of its cultivation followed quality planting materials in desired quantity. Dragon fruit can be propagated by various ways both sexually via seeds as well as asexually via stem cuttings, grafting and also via micropropagation. In this review various methods of propagation of dragon fruit are described along with some propagation aspects related to dragon fruit on which very limited information is available. Potential areas on dragon fruit propagation that require further research to generate more data in order to improve the techniques are also discussed.

Selecting thermal tolerant strains of entomopathogenic fungi to control Ceratitis capitata (Wiedeman) in tropical semi-arid conditions

Although it is usual, using constant temperature to select thermo-tolerant entomopathogen (EF) strains could discard potentially efficient biocontrol agents (BCA). The objectives of this work were to select virulent EF against C. capitata and evaluate the effect of continual and fluctuating temperature on fungal development and virulence. Initial experiments compared the effect of constant temperatures (CT) (20, 25, 30, 35, and 38 °C) and simulated intraday temperature variation (SIV) (20–38 °C) over conidial germination, mycelial growth, and insect mortality. Temperatures ≥ 35 °C in the CT experiments significantly reduced conidial germination, and the strains of Beauveria bassiana BbLCB81 and BbLCB289 showed the highest conidial germination and mycelial growth. SIV also caused a significant effect, and M. anisopliae MaLCB62 showed the highest conidial germination and mycelial growth. Applying EF strains as toxic baits in CT showed that the highest mortality occurred at 30 °C, and BbLCB62 and BbLCB289 showed the largest insect mortality at 38 °C. Survival analysis showed a slight increase in the average survival time (ST50) at 30 °C. In SIV conditions, MaLCB56 and BbLCB289 were highly virulent. In a field cage experiment at a warmer temperature, BbLCB62 was the most virulent strain according to the M-C test comparing survival curves. However, confirmed accumulated mortality on the 10th day was similar to the moderately tolerant BbLCB289 (Tukey, p < 0.05). During winter, all EF strains showed similar mortality on 10th day (Tukey, p < 0.05), but a significant difference in the survival analysis. EF strains with mild temperature tolerance can be applied in seasons with high temperatures, and BbLCB62 and BbLCB289 were selected as potential biocontrol agents against C. capitata.

Impact of paclobutrazol on gibberellin-like substances and soluble carbohydrates in pear trees grown in tropical semiarid

Given that Brazilian pear production is unable to meet the annual demand, to consider the possible expansion to non traditional growing regions, turns interesting. Even though under tropical semi-arid conditions pear trees have vigorous vegetative growth, a negative influence on flower bud differentiation and formation affects fruit yield. Our study aimed to evaluate the inhibition efficiency of paclobutrazol (PBZ) on gibberellin biosynthesis, vegetative growth, and carbohydrate production in two pear-treecultivars (‘Santa Maria’ and ‘Hosui’) grown under semi-arid conditions. To this end, two experiments were conducted, one for each pear-tree cultivar. The experimental designs consisted of randomized blocks, with factorial arrangement (5x2x4), corresponding to PBZ doses (0.0, 0.5, 1.0, 1.5, and 2.0 g per linear meter of plant canopy), PBZ application forms (soil and foliar), and evaluation dates (30, 60, 90, and 120 days after application). Both soil and foliar applications inhibited gibberellin biosynthesis in both cultivars, especially after 120 days of application. PBZ affected leaf total soluble carbohydrates and reduced sprout growth in both cultivars. Although PBZ can be potentially used in pear management, further studies are still required to determine specific management practices in tropical semi-arid zones. Highlights: Inhibition of gibberellin biosynthesis is more efficient with soil application of paclobutrazol. Soil application of paclobutrazol results in greater production of carbohydrates. There is a difference in sensitivity to the effects of paclobutrazol among pear varieties. The non-application of paclobutrazol results in late maturation of the branches, compromising floral induction.

Concentration and Uptake of Micronutrients (Fe, Zn, Cu and Mn) in Soybean and Wheat under Organic, Biodynamic and Inorganic Nutrient Management in Semi-arid Tropical Conditions of Central India

ABSTRACT In the present investigation, the concentration and uptake of four micronutrients (iron-Fe, zinc-Zn, copper-Cu, and manganese-Mn) in soybean (Glycine max, cv. JS 335) and wheat (Triticum durum, cv. HI 8498) crops under organic, biodynamic, and inorganic nutrient management was studied. The experiment was laid out in a randomized block design with seven treatments in four replications. The treatments involved different nutrient inputs, namely, organic manure (OM) (T1); biodynamic preparation (BD) (T2); OM+ panchagavya (OM+PG) (T3); OM+BD (T4); OM+PG+BD (T5); control (T6); and recommended dose of fertilizers (RDF) (T7). Cattle dung manure on N equivalent basis to soybean in kharif and cattle dung manure (CDM) + vermicompost (VC) + poultry manure (PM) (1:1:1 on N equivalent basis) to wheat were applied as organic manure, whereas nutrients were supplied in the form of chemical fertilizers in RDF treatment. The results revealed that the micronutrient concentration in soybean seed under organic nutrient management registered an increment of 13–16% in Fe, 16–19% in Zn, 20–23% in Cu, and 19–25% in Mn over the treatment T7 (RDF). Similarly, an increment of 16–19% in Fe, 21–27% in Zn, 20–23% in Cu, and 20–26% in Mn content of wheat grain was also observed over RDF. The micronutrient uptake by soybean-wheat sequence was found higher under organic treatments (Fe:20–29%; Zn:13–22%; Cu:11–19%; and Mn:12–19%) as compared to RDF. The availability of Fe, Zn, Cu, and Mn was increased by 30–36%, 32–45%, 5–12%, and 20–36%, respectively, under organic treatments over RDF.

Irrigation with Wastewater and K Fertilization Ensure the Yield and Quality of Coloured Cotton in a Semiarid Climate

Treated domestic sewage (TDS) can contribute to plant nutrition and improve crop production. However, there are no data for its use in coloured cotton under a deficit or excess irrigation in combination with potassium fertilization rates (KRs), mainly under semiarid tropical conditions. The research was conducted using a randomized complete block design in a factorial scheme (5 × 5, irrigation regimes vs. potassium rates), plus an additional treatment as the control ((5 × 5) + 1). The treatments consisted of five TDS irrigation regimes (50, 75, 100, 125, and 150% of crop evapotranspiration—ETC) and five KRs (0, 50, 100, 150, and 200% of the local crop recommendation), plus a control—CT— (irrigated with fresh water at 100% ETC and fertilized according to the local crop recommendation) and four replications. The optimal crop yield, water use efficiency, and potassium use efficiency were obtained when TDS was applied as a deficit irrigation treatment of 75% of ETC or as full irrigation (100% of ETC) and when associated with moderate increases in K fertilization. These treatments also resulted in a better fibre quality when compared to the CT, meeting or exceeding the requirements of the textile industry. Therefore, moderate deficit irrigation with TDS is indicated as an important strategy to save fresh water and to reduce the use of fertilizers, while having the potential to increase profit margins for cotton production in tropical semiarid regions.

Performance of graft combinations of Passiflora spp. under tropical semi-arid conditions in Brazil

Performance of graft combinations of Passiflora spp. under tropical semi-arid conditions in Brazil

Aerobic Rice with or without Strategic Irrigation in the Subtropics

Modern rice varieties adapted to aerobic (dryland) conditions have expanded to new rice growing systems thanks to their plasticity in adapting to rainfed and irrigated conditions. This is important because, as water becomes scarce in paddy rice regions (as it is already in Australia), there will be a move towards tropical to subtropical dryland rainfed rice with attendant problems of drought and low temperature. To assess rice adaptability in the wet season of the semi-arid subtropical conditions of coastal central Queensland, field experiments were established for a late season (in January) planting in 2014 and early season planting in November 2015 with 13 varieties developed by Australian Agriculture Technologies (AAT) Ltd were seeded in a vertisol soil. This was to assess their adaptation to rainfed conditions and their response to strategic irrigation. Water scarcity and low temperature prior to and at flowering were important factors constraining yield. Early flowering varieties in the late season planting escaped the otherwise cold and drought stress during the reproductive stage and had higher yields. In the second year, earlier planting made possible with strategic irrigation avoided the low temperature constraint on yield, but without follow-up strategic irrigation, yields were still low. The average yield of varieties increased from 1.5 times (AAT 4) to 16.3 times (AAT 15) with strategic irrigation compared with rainfed yields averaged across years. The increase in yield with strategic irrigation was associated with a greater leaf area index, spikelet fertility, and instantaneous water use efficiency during flowering. Strategic irrigation concentrated roots in the top 15 cm, but differences in yield between varieties under rainfed conditions were not related to root properties. It is important to consider variations in flowering time, yield potential, and drought patterns when developing rice varieties for rainfed semi-arid tropical conditions, as well as when quantifying the benefits of strategic irrigation.

Advances in mango ‘Keitt’ production system: PBZ interaction with fulvic acids and free amino acids

The present study aimed to assess the effectiveness of fulvic acids and free amino acids in potentiating the effect of paclobutrazol on flowering management of mango 'Keitt' grown in tropical semiarid. The experiment was carried out simultaneously in two orchards with the same mango cultivar and management characteristics. The experiment was performed from 2017 to 2018 in two experimental orchards located in Cabrobó, State of Pernambuco, Brazil. The experimental design was randomized blocks with four treatments, five replications and four trees per replication. The treatments consisted of several combinations of paclobutrazol with fulvic acids and free amino acids, as follows: T1: paclobutrazol + water (control); T2: paclobutrazol + fulvic acids; T3: paclobutrazol + free amino acids; and T4: paclobutrazol + fulvic acids + free amino acids. According to the results, the use of fulvic acids, free amino acids, or both affect the PBZ action in ‘Keitt’mango trees. The addition of fulvic acids to PBZ improves its efficiency by inhibiting gibberellin content at the most appropriate time, maintaining carbohydrate, protein and amino acids levels, uniform flowering and, consequently, providing higher yield in mango ‘Keitt,’ and therefore may be recommended for growing mangoes in tropical semiarid conditions.

Agronomic performance of seedless table grape genotypes under tropical semiarid conditions

ABSTRACT The Sao Francisco Valley is the main producing region of table grape in Brazil. The objective of this work was to evaluate the agronomic performance and physicochemical characteristics of 14 seedless table grape genotypes to select those with potential to be used in commercial crops in the Sao Francisco Valley, Brazil, or as parents in breeding programs. The experiment was carried out over five crop seasons (2014 to 2018), in Petrolina, PE, Brazil. The treatments consisted of 14 seedless table grape genotypes. The results showed significant effects for all variables evaluated. The highest estimated yield per production cycle were found for ‘Marroo Seedless’ (26.5 t·ha-1), ‘BRS Linda’ (26.4 t·ha-1), ‘CNPUV 23’ (24.9 t·ha-1), ‘A1105’ (24.3 t·ha-1),and ‘A Dona’ (20.2 t·ha-1). Soluble solid (SS) content varied from 13.35 oBrix (‘CNPUV 23’) to 21.63 oBrix (‘A Dona’). The titratable acidity (TA) of the genotypes varied from 0.27 g·100 mL-1 (‘CNPUV 23’) to 0.72 g·100 mL-1 (‘Crimson Seedless’). Principal component analysis showed that the first three principal components explained 81.9% of the data variance, and grouped the best genotypes for production components and fruit chemical composition on different sides of the X-axis. These results allowed the identification of a group of seedless grape cultivars that can be used for commercial crops or as parents for controlled crossings in a local table grape breeding program.

Impact of fulvic acid and free amino acids on paclobutrazol absorption by ‘Keitt’ mango

This study evaluated the impact of fulvic acid and free amino acids on paclobutrazol soil residue, their absorption and effects on ‘Keitt’ mango grown in tropical semi-arid environmental conditions. The experiment was carried out from 2017 to 2018 simultaneously in two orchards with the same plants and management characteristics, located in Cabrobó, Pernambuco, Brazil. The experimental design was randomized blocks with four treatments, five replications and four plants per replication. The treatments consisted of paclobutrazol combinations with acid fulvic and free amino acids, as follows: Treatment 1: paclobutrazol + water (control); Treatment 2: paclobutrazol + fulvic acids; Treatment 3: paclobutrazol + free amino acids; and Treatment 4: paclobutrazol + fulvic acids + free amino acids. According to the results, the use of fulvic acids, free amino acids or both affects the paclobutrazol absorption by 'Keitt' mango. The addition of fulvic acid to the paclobutrazol improves the absorption of this molecule by the plant, with greater inhibition of vegetative growth of 'Keitt' mango and lower soil residues.

The Carboniferous-mid Permian successions of the Northern Apennines: new data from the Pisani Mts. inlier (Tuscany, Italy)

This paper updates and partially modifies the knowledge of the geological-palaeoenvironmental and geodynamic framework of the Tuscan segment of the Variscan Chain in Tuscany during Permian times. Particularly, it adds new data on the contact between the upper Carboniferous-lower Permian San Lorenzo schist (SLs) and the mid-Permian Asciano breccia and conglomerate (Abc) clastic formations in the Pisani Mts. metamorphic inlier which represents one of the pinning point outcrops for the study of the upper Paleozoic sequences in the Northern Apennines. Their sharp unconformable contact is well-documented in the literature at map and outcrop scale and was ascribed to the Saalian phase of the Variscan orogeny that would have occurred in correspondence of a climatic change from equatorial to an semi-arid tropical conditions. New geological investigations on the SLs and Abc allowed us to identify the finding of a continuous stratigraphic section in the Pian della Conserva locality (northwestern Pisani Mts.) where the organic matter-rich SLs conformably passes upwards to the reddish immature, mainly coarse-grained deposits of Abc through a decametric transition zone. The section was studied in detail from a lithological-sedimentological point of view and sampled for petrographic, mineralogic and chemical studies. The data show that the passage from SLs to Abc testifies a main change from an equatorial, wet fluvial-lacustrine environment to a well-drained, alluvial fan systems in a monsoon- like climate. This event can be related to the reactivation of the previous late Carboniferous-lower Permian shear zones during the mid-Permian times that produced morpho-tectonic highs subjected to a rapid erosion and the formation of unconformities, whereas the presence of a few residual fluvial plain areas, characterized by dysoxic conditions, is documented by the gradual passage between SLs and Abc in the Pian della Conserva section. In addition, the presence of a metavolcanoclastic or metaepiclastic layer was also recognized in the uppermost part of the SLs and it represents the first evidence of a late Carboniferous-early Permian volcanic event in the Northern Apennines.

Trellis systems, rootstocks and season influence on the phenolic composition of ‘Chenin Blanc’ grape

ABSTRACT: The biosynthesis of phenolic compounds might be influenced by environmental factors, such as solar radiation, temperature and relative air humidity, and production system. Some components of the production system, particularly the trellis system and rootstock, might change the phenolic composition of grapes due to microclimate of the cultivation region. In this study, the phenolic profile of ‘Chenin Blanc’ grapes was characterized with different trellis systems and rootstocks in two consecutive production cycles by using high-performance liquid chromatography under tropical semi-arid conditions. In the second production cycle (Jan-May/2016), accumulation of (-) - epicatechin gallate and (-) - epigallocatechin gallate was higher when vigorous rootstocks were trellised to the lyre system, whereas the lyre system associated to rootstock ‘SO4’ resulted in higher rutin accumulation in the same cycle. There was little influence of the factors studied on trans-resveratrol and piceatannol accumulation. However, a higher accumulation of piceatannol was observed in the second productive cycle compared to cis-resveratrol and trans-resveratrol. This study highlights that accumulation of phenolic compounds is influenced not only by environmental factors typical of the production year season, but also by the trellis system and rootstock adopted. The identification of phenolic compounds in the accumulation stimulated by the combination of trellis system, rootstock, and production season allows to differentiate grape quality and add value to products derived from such combination in a tropical semi-arid region.

Polycoated urea performance in wheat under semi-arid tropics

Field experiments were conducted using wheat cultivar HD-2967 during Rabi 2016-17 for evaluating efficiency of polycoated urea (PCU) (42% N) viz. neem coated urea (NCU) (46% N) under semi-arid tropical conditions in Tarn Taran district of Punjab, India. Treatments comprised of T1 100% N through NCU (3-Splits), T2 100% N through PCU (3-Splits), T3 100% N through PCU (1-Split), T4 75% N through PCU (1-Split). Results revealed that T3 treatment had highest grain as well as straw yields followed by T1, T2 and T4 (for grain yields) while T4, T1 and T2 (for straw yields) though in a non-significant mode. Crop biomass reported to be significantly higher in T3 in January while become at par during February and March, 2017. Among yield attributes viz. spike length, grains spike−1 and 1000 grain weight reported to be highest in T3 while tillers reported to be highest in the T2 treatment. Nitrogen concentration (%) in plant biomass reported to be highest in T3 followed by T1, T4 and T2, respectively. Among, nutrient efficiency parameters viz. agronomic efficiency (kg N ha−1) and physiological efficiency (kg N ha−1) T3 (100% PCU (1 splits) reported to have highest values than T1 and T2, where as recovery efficiency (%) found to be highest in T4 followed by T3, T2 and T1, respectively. Hence, being a slow release fertilizer 100% PCU (42% N) (1-Split) will serve the purpose for sustainable wheat production in semi-arid tropics.

Rootstocks for the new seedless table grape ‘BRS Vitória’ under tropical semi-arid conditions of São Francisco Valley

ABSTRACT ‘BRS Vitoria’ is the most important Brazilian table grape cultivar in the domestic and foreign markets, standing out for the seedleness, pleasant flavor, high yield and mildew resistance. The aim of the present study was to determine the effect of the rootstock on the yield, production components, vigor, and physical and chemical characteristics of the ‘BRS Vitória’ grape under irrigation in the Brazilian semi-arid region. The experiment was conducted over eight consecutive production cycles in the period from 2015 to 2018 in a commercial area in the Senador Nilo Coelho project, Petrolina, PE. The treatments were represented by seven rootstocks: ‘IAC 572’, ‘IAC 766’, ‘IAC 313’, ‘Harmony’, ‘SO4’, ‘Paulsen 1103’, and ‘Freedom’, using a randomized block experimental design with four replications. The results were variable among production cycles, with significant effects of the rootstock in some cycles and/or in the overall mean of the cycles. The variables of pruning weight, sprouting, bud fertility, and titratable acidity were not affected by the rootstock in any of the production cycles evaluated in this study. ‘Harmony’ rootstock promoted greater berry mass and diameter but reduced the soluble solids content. Vines of ‘BRS Vitória’ showed moderate vigor, high bud fertility and yield, satisfactory characteristics of bunch and berry, sugars and acids content that meet the requirements of the most demanding markets in all the rootstocks evaluated in this study.

Yield components of the new seedless table grape ‘BRS Ísis’ as affected by the rootstock under semi-arid tropical conditions

The new seedless table grape cultivar BRS Ísis has high bud fertility, yield and tolerance to downy mildew; its planted area is rapidly increasing in the Vale do São Francisco region in the Northeast of Brazil. The aims of the present study were to evaluate the yield performance, yield components, physical and chemical characteristics of the fruit of the cultivar BRS Ísis grafted onto different rootstocks in irrigated growing in the semi-arid region of Brazil. The experiment was conducted in a commercial vineyard in Petrolina, Pernambuco, over six production cycles in the period 2015-2018. The treatments were represented by the rootstocks IAC 572, IAC 766, IAC 313, Freedom, Harmony, Paulsen 1103, and SO4 in a randomized block design with four replications. There was a greater effect of the production cycle than of the rootstock on all the variables studied, with significant differences between rootstocks in some cycles and/or in the overall mean of the production cycles. Mean production of the six cycles was greatest for IAC 572, at 27 Kg (45 ton/ha/cycle) and 100 clusters per grapevine. The physical characteristics of the clusters and berries and chemical composition of the grape achieved the standards described for the cultivar BRS Ísis and market demands for all the rootstocks.