INFLUENCE OF ORGANIC FERTIZATION ON THE FRUIT MORPHOLOGY AND PRODUCTION OF MANGO (Mangifera indica L.) VAR. KENT

Purple maize native to the Peruvian Andes, is a key source of anthocyanins with notable antioxidant properties. In field cultivation, seed germination and early seedling development are critical stages influencing crop establishment and yield. This study evaluated the effects of three stimulants, namely seaweed extract, sulfur dioxide, and milk whey, on the germination and early development of creole and hybrid purple maize varieties under controlled laboratory and greenhouse conditions. Seeds of each variety were subjected to seven pre-sowing treatments in a completely randomised design with three replications. Germination indices (imbibition rate, germination percentage, speed, and index) were assessed, followed by evaluation of eleven biometric traits at 15 days after emergence. Seaweed extract significantly enhanced plant height, shoot dry weight, and leaf dimensions in both varieties, particularly at 1.5 L/200 L. Sulfur dioxide improved root biomass and length, while low-dose milk whey treatments favoured moderate root growth. Creole seeds showed higher vigour in early germination, while hybrids responded better to stimulant application during early development. These findings demonstrate that biostimulants, particularly seaweed extract, can effectively enhance early growth traits in purple maize, offering potential for improving seedling establishment in sustainable production systems.

Potato (Solanum tuberosum L.) is the third most important food crop worldwide and a cornerstone of food security across the Andean region. However, its production is increasingly threatened by the potato psyllid Bactericera cockerelli (Šulc), the vector of Candidatus Liberibacter solanacearum, the causal agent of the purple-top complex associated with zebra chip disease, which severely reduces both tuber yield and quality. This study was conducted from September 2024 to February 2025 in the province of Huancabamba, Peru, to evaluate the efficacy of biological and chemical control agents against B. cockerelli under field conditions. A randomized complete block design was implemented with five treatments and four replicates, totaling 20 experimental units, each consisting of 20 potato plants (S. tuberosum L.), of which 10 plants were evaluated. Treatments included an untreated control (T0), a chemical control (thiamethoxam + lambda-cyhalothrin, abamectin, and imidacloprid) (T1), and three biological control agents: Beauveria bassiana CCB LE-265 (>1.5 × 10¹⁰ conidia g⁻¹) (T2), Paecilomyces lilacinus strain 251 (1.0 × 10¹⁰ conidia g⁻¹) (T3), and Metarhizium anisopliae (1.0 × 10¹⁰ conidia g⁻¹) (T4). Foliar applications targeted eggs, nymphs, and adults of the psyllid. Results indicated that B. cockerelli mortality across developmental stages was lower under biological treatments compared with T1, which achieved the lowest probability of purple-top symptom expression (46%) and a zebra chip incidence of 60.60%. Among the biological agents, M. anisopliae (T4) reduced incidence to 56.60%, while P. lilacinus (T3) demonstrated consistent suppression of nymphal populations. In terms of yield, T1 achieved the highest tuber weight (198.86 g plant⁻¹) and number of tubers (7.74 plant⁻¹), followed by T3 (5.08) and T4 (4.24). Nevertheless, all treatments exhibited low yields and small tuber sizes, likely due to unfavorable environmental conditions and the presence of the invasive pest. Overall, chemical control was more effective than biological agents; however, the latter showed considerable potential for integration into sustainable pest management programs. Importantly, vector suppression alone does not guarantee the absence of purple-top complex symptoms or zebra chip disease in potato tubers.

Background: Cotton is a crop of great socioeconomic interest in the textile industry in Peru, however, it is sown directly in the field where it presents irregular germination. Objective: To evaluate the effect of four doses of hydrogen peroxide and two imbibition times on the germination and initial growth of cotton. Methodology: The commercial hydrogen peroxide CP (H2O2 at a concentration of 3 g 100 mL-1) was used in the treatments: T0 (control- distilled water), T1 (10% CP), T2 (30% CP), T3 (50% CP), T4 (100% CP) subjected to 6 and 12 h of imbibition. Germination evaluations were made: germination percentage (GP), germination speed (GS), germination index (GI), Biometry: seed weight (SW), stem length (ST), number of leaves (NL) and root length (RL). Stem biomass: fresh weight (SFW) and dry weight (SDW), and root biomass: fresh weight (RFW) and dry weight (RDW). Results: T3-6 h improved germination variables. T1-6 h improved biometry and biomass variables. SW presented a negative correlation with NL. NL was positively correlated with SDW. SDW was positively correlated with SFW. Also, SFW with RL, RDW and RFW. RL with RDW. RDW with RFW and ST. The RFW with ST. Implications: The use of H2O2 increases germination and biomass of cotton seedlings. Conclusion: T3-6 h improved germination variables. However, T1-6 h improved biometry and biomass variables.

El uso de residuos orgánicos en la elaboración de los sustratos fomenta una economía circular y reduce la contaminación ambiental. Por tal razón, el objetivo de esta investigación fue evaluar el efecto de diferentes sustratos y la aplicación de silicio en la propagación del portainjerto de palta zutano. Los sustratos fueron: arena (A), compost (C), suelo agrícola (SA), silicio comercial (SiC) y turba (T). Los tratamientos evaluados fueron: T1 (100 % A control); T2 (75 % A + 25 % C); T3 (50 % A + 20 % C + 20 % T + 10 % SiC); T4 (25 % A + 25 % C + 25 % T + 25 % SiC); T5 (10 % A + 25 % C + 40 % T + 25 % SA); T6 (25 % A + 15 % C + 10 % SiC +50 % SA); T7 (40 % T + 10 % SiC + 50 % SA); y T8 (10 % T + 10 % SiC + 80 % SA). Además, se evaluaron: altura de planta (AP) cm; diámetro de tallo (DT) cm; número de hojas (NH); longitud de raíces (LR) cm; peso fresco de raíces (PFR) g; y volumen de raíces (VR) mL. Para ello se trabajó un diseño de bloques completos al azar (DBCA) con 8 tratamientos y 3 repeticiones (unidad experimental = 8 plantas) con 192 plantas. El estudio comprendió un análisis ANOVA y multivariado. El tratamiento T5 mejoró la AP (43 cm), DT (0.3 cm) y NH (11.33). Los tratamientos T7 y T8 incrementaron la LR con 44.33 y 40.67 cm respectivamente; asimismo, el T8 mejoró el PFR con 45.5 g y el T2 incrementó el VR con 34 mL. La incorporación de SiC en el sustrato mejoró la LR. En el análisis de componentes principales (ACP) se formaron 2 dimensiones (D) que agruparon las variables en estudio: D-I (AP, DT, LR, VR) y D-II (PFR, NH), en las que se presentó una alta correlación de dependencia positiva (r > 0.75) entre AP, DT y VR.

Mango (Mangifera indica L.) is a tropical fruit tree characterized by vigorous growth and high fruit production, making it one of Peru’s main export crops. However, its extensive vegetative development requires substantial space, limiting productivity per unit area. This study evaluated the effects of rootstock and interstock combinations on agronomic traits and fruit biometrics, highlighting the potential of interstocks to modulate tree vigor in mango orchards of Peru’s dry forest region. A total of 216 trees were established using ‘Chulucanas’ and ‘Chato’ as rootstocks and ‘Chulucanas,’ ‘Chato,’ ‘Irwin,’ and ‘Julie’ as interstocks, apically grafted with the ‘Kent’ cultivar, with a spacing of 6.0 m × 6.0 m. Tree performance was assessed after 10 years during the 2017–2019 growing seasons in Piura, Peru, under a randomized complete block design (2 × 4 factorial). The combination of the ‘Chulucanas’ rootstock with ‘Chulucanas’ and ‘Julie’ interstocks reduced tree height by 10.94% and 11.70%, respectively, facilitating orchard management and potentially increasing planting density. Yield varied significantly among growing seasons, with a 15% reduction in 2017 attributed to El Niño–Southern Oscillation (ENSO)-related increases in temperature and rainfall that affected flowering and fruit set. These results underscore the importance of cultivar selection and climate-adaptive strategies to sustain mango productivity in regions prone to climatic variability.