PENGARUH PUPUK HAYATI DENGAN KOMPOSISI MIKROORGANISME YANG BERBEDA TERHADAP PERTUMBUHAN TANAMAN

Biofertilizer can be used to replace chemical fertilizer so that soil quality is maintained and soil pollution can be avoided. The study aimed to determine the effect of biofertilizers with different compositions of microorganisms on the growth of maize plants. The research was carried out in a greenhouse. Maize plants were fertilized by two kinds of biofertilizers with different compositions of microorganisms. The first biofertilizer contained Azotobacter sp, Azospirillum sp, Rhizobium sp, Trichoderma sp, and Lactobacillus sp, and the second biofertilizer contained Strenotrophomonas sp. and Paenibacillus polymyxa. As controls, maize plants were fertilized by sterilized those biofertilizers. The results showed that the second biofertilizer increased the dry weight of the maize plant. Meanwhile, the first biofertilizer did not increase it. Several things must be considered in the application of biofertilizers, such as the composition of microorganisms, type of plant, level of fertilization, and the method of applying fertilizer to the plant.

The predatory mite Neoseiulus californicus (Acari: Phytoseiidae) does not respond for volatiles of maize infested by Tetranychus urticae (Acari: Tetranychidae)

Among the plants defense mechanisms, the induction and emission of volatile organic compounds, which can be used to attract natural enemies, such predators insects. Although well studied, the induction of plant volatiles that attract natural enemies can vary according to intensity of infestation of herbivores and the species of host plant. We investigated the olfactory behavioral responses of the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) to the volatiles of infested maize (Zea mays) plants by the two-spotted spider mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) in early and advanced infestations. The Bt (Viptera) maize cultivar Impact® was used for tests the behavior of N. californicus. After initial and advanced infestations, the phytophagous mites T. urticae were removed, and the plants were tested using a “Y” olfactometer. The following treatments were evaluated: air vs. air, uninfested plants vs. air, uninfested plants vs. plants infested with 10 females of T. urticae, uninfested plants vs. plants infested with 100 females of T. urticae, uninfested plants vs. plants infested with 200 females of T. urticae and plants infested with 10 vs. plants infested with 200 females of T. urticae. The predatory mite N. californicus did not show preference to the treatments tested, suggesting that maize plants infested by T. urticae do not induce volatiles capable of attracting the predatory mite N. californicus. We concluded that N. californicus is not attracted by maize plants infested by T. urticae.

Utilization of Tithonia diversifolia and sugarcane leaves to improve soil properties and plant growth on a sandy soil of Malang, East Java

A study on the addition of organic matter of different qualities was carried out to improve plant growth on a degraded sandy soil of Bambang Village, Wajak Malang, East Java. Two potential sources of organic matter in Bambang Village are Tithonia diversifolia and sugarcane leaves. This study aimed at elucidating the changes in some chemical properties of a degraded sandy soil of Malang, East Java, and nutrient uptake and growth of maize plants by applying mixtures of Tithonia diversifolia and sugarcane leaves of different quality. Treatments tested in this study were mixtures of Tithonia diversifolia leaves and sugarcane leaves at various proportions (%w/w), i.e. 100% Tithonia diversifolia leaves (T1), 100% sugarcane leaves (T2), 75% Tithonia diversifolia leaves + 25% sugarcane leaves (T3), 50% Tithonia diversifolia leaves + 50% sugarcane leaves (T4); without organic matters (T6), and control, without organic matter and inorganic fertilizers (T7). The results showed that the application of Tithonia diversifolia and sugarcane leaves affected soil pH, soil exchangeable bases, maize growth, and nutrients uptake. Nutrients taken up by maize plants significantly increased with the addition of Tithonia diversifolia leaves, either alone or in combination with sugarcane leaves. The application of 100% sugarcane leaves did not significantly affect maize growth and nutrient uptake.

Endemic and invasive Coccinellidae associated with maize (Zea mays L.) fields, in Manabi province, Ecuador

Maize (Zea mays L.), which is considered an important cereal everywhere, is widely cultivated in different agroecological conditions. Throughout their phenological stages, maize crops are attacked by pests and diseases, and in Ecuador these phytosanitary problems are usually counteracted with applications of pesticides. However, knowledge of beneficial entomofauna is fundamental to guide pest management programs. As part of this objective, the Coccinellidae species present in maize fields in localities (Santa Ana, Colon, and Danzarin) in Manabí province were identified. In each zone, maize plants were sampled from 2018–2019. A total of 2,654 specimens belonging to 14 taxa were collected in this study, of which Cheilomenes sexmaculata, Cycloneda sanguinea, Hippodamia convergens, Hyperaspis arida, and Psyllobora confluens were found in all the studied areas. Hyperaspis arida and Diomus apollonia are reported for the first time in Ecuador.

Efficacy of Zn-Aspartate in comparison with ZnSO4 and L-Aspartate in amelioration of drought stress in maize by modulating antioxidant defence; osmolyte accumulation and photosynthetic attributes

Human population is exceeding beyond the carrying capacity of earth resources and stresses like water shortage faced by the plants is jeopardizing the food security. Current research study was aimed to investigate the potentials of Zn-Aspartate (Zn-Asp), Zn-Sulphate (ZnSO4) and L-Aspartate (L-Asp) to be used as osmolytes and role of various levels of these chemicals in combating drought stress in maize plants in Punjab, Pakistan. Study was performed on two plots corresponding to drought and controlled environments. The lamina of maize plants was sprinkled row wise with various treatments including No spray (NS), water sprinkle (WS), sprinkle with ZnSO4 0.25% and 0.50%, sprinkle with Zn-Asp 0.25% and 0.50% and Foliar sprinkle of L-Asp 0.5% and 1%, respectively. Role of major osmoprotectants and secondary metabolites was analyzed and positive changes were found in total soluble sugars (41.16), flavonoids (5387.74), tocopherol content (9089.18), ascorbic acid (645.27) and anthocyanin (14.84) conc. which assists in mitigating drought menace on maize. Shoot mineral ions (Ca, K, Zn, P, Mg and N) status of water stressed maize plants was also analyzed and it was found that application experimental dose enhanced their availability to crop. Physio-biochemical studies were performed on antioxidants enzymes like superoxide dismutase (SOD), peroxidase (POD), carotenoid content (CC), malondialdehyde, hydrogen peroxide, aspartate and free amino acid contents. The activity of SOD was increased by 28.5% and activity of POD was increased by 33.33% due to foliar applied 0.5% Zn-Asp under drought stress. Photosynthetic pigments (chlorophyll A, B and total chlorophyll content) analysis was also carried out in this study. It was found that conc. of different chlorophylls pigments increased (chl-A: 2.24, chl-B: 25.12, total chl: 24.30) which enhanced photosynthetic activity culminating into better growth and yield). The level of malondialdehyde and hydrogen peroxide decreased by 43.9% and 32.8% respectively on treatment with 0.5% Zn-Asp proving the efficacy of the treatment in drought amelioration. Study reveals that Zn-Asp induced modulations are far better than conventional sulphate salts in mitigating water scarce environment. Current study recommends the use of the Zn-Asp to meet the global food and agricultural challenges as compared to ZnSO4 and L-Asp due to its better drought amelioration properties. This research provides valuable informations which can used for future research and practical use in agriculture fields by indigenous and other people to enhance yield of maize to meet the food necessities of country.

Development and Evaluation of Stable Sugarcane Mosaic Virus Mild Mutants for Cross-Protection Against Infection by Severe Strain

Sugarcane mosaic virus (SCMV; genus Potyvirus) induces maize dwarf mosaic disease that has caused serious yield losses of maize in China. Cross-protection is one of the efficient strategies to fight against severe virus strains. Although many mild strains have been identified, the spontaneous mutation is one of the challenging problems affecting their application in cross-protection. In this study, we found that the substitution of cysteine (C) at positions 57 or 60 in the zinc finger-like motif of HC-Pro with alanine (A; C57A or C60A) significantly reduced its RNA silencing suppression activity and SCMV virulence. To reduce the risk of mild strains mutating to virulent ones by reverse or complementary mutations, we obtained attenuated SCMV mutants with double-mutations in the zinc finger-like and FRNK motifs of HC-Pro and evaluated their potential application in cross-protection. The results showed that the maize plants infected with FKNK/C60A double-mutant showed symptomless until 95 days post-inoculation and FKNK/C60A cross-protected plants displayed high resistance to severe SCMV strain. This study provides theoretical and material bases for the control of SCMV through cross-protection.

Inoculation of Herbaspirillum Seropedicae Increases Biomass in Maize Roots in the Early Stages of Plant Development

Herbaspirillum seropedicae is a plant growth-promoting bacteria isolated from diverse plant species. In this work, the main objective was to investigate the efficiency of H. seropedicae strain SmR1 in colonizing and increasing maize growth in the early stages of development under greenhouse conditions. Inoculation with H. seropedicae resulted in 10.51 and 19.43% in mean of increase of root biomass concerning non-inoculated controls, mainly in the initial stages of plant development, at 21 days after emergence (DAE). Quantification of H. seropedicae in roots and leaves was performed by quantitative PCR.. H. seropedicae was detected only in maize inoculated roots by qPCR, and a slight decrease in DNA copy number g−1 of fresh root weight was observed from 7 to 21 DAE, suggesting that there was initial effective colonization on maize plants. H. seropedicae strain SmR1 efficiently increased maize root biomass exhibiting its potencial to be used as inoculant in agricultures systems.