Lanatus Var Research Articles

Morphophysiological and biochemical investigation of the potential of citron watermelon (Citrullus lanatus var. citroides) rootstock under different irrigation regimes

Morphophysiological and biochemical investigation of the potential of citron watermelon (Citrullus lanatus var. citroides) rootstock under different irrigation regimes

Phenotypic Characterization of Citron Watermelon (Citrullus lanatus var. citroides) Genotypes for Bioenergy Production

Citron watermelon (Citrullus lanatus var. citroides) is an important climate smart crop, characterized by high oil content in the seeds and it is a popular fruit in southern Africa. To determine best performing genotypes eight phenotypic traits were assessed to identify cultivars with potential for biodiesel production. A field experiment was conducted at Sebele Agricultural Research Station, in Southern Botswana, during 2019 to 2020 cropping season. Four (4) melon genotypes were planted in a Randomized Complete Block Design replicated three times and eight (8) characters were assessed. Except seed oil content (26.6%) there was significant (P < 0.05) difference among all the traits, an indication of higher genetic diversity in the selected citron watermelon. SC1-Sesoswane, exhibited highest seed yield (1540 kg/ha) and oil yield (435.03 kg/ha) while MMB-280-Lerotse recorded lowest seed yield and oil yield of 548.1 kg/ha and 144 kg/ha respectively. There was a significant correlation of (0.9) between oil yield (kg/ha), number of fruits produced, and seed yield (kg/ha), an indication that increasing the seed yield will positively increase the amount of oil produced. This study revealed the potential bioenergy production of the four cultivars. However, SC1-Sesoswane appears a more promising alternative cultivar for feedstock for biodiesel production.

Heterosis of Yield and Quality Traits of Watermelon [Citrullus lanatus var. lanatus (Thunb.)] Hybrids and Their Performance in the Sub-Tropical Region

Heterosis of Yield and Quality Traits of Watermelon [Citrullus lanatus var. lanatus (Thunb.)] Hybrids and Their Performance in the Sub-Tropical Region

Anti-Influenza Virus Activity of Citrullus lanatus var. citroides as a Functional Food: A Review.

Influenza is an acute respiratory illness caused by the influenza virus, in response to which vaccines and antiviral drugs are administered. In recent years, the antiviral effects of plants and foods have garnered attention. This review is the first to summarize the therapeutic properties of wild watermelon (Citrullus lanatus var. citroides) against influenza from a phytochemical viewpoint. Wild watermelon is a wild plant with significant potential as a therapeutic candidate in antiviral strategies, when focused on its multiple anti-influenza functionalities. Wild watermelon juice inhibits viral growth, entry, and replication. Hence, we highlight the possibility of utilizing wild watermelon for the prevention and treatment of influenza with stronger antiviral activity. Phytochemicals and phytoestrogen (polyphenol, flavonoids, and prenylated compounds) in wild watermelon juice contribute to this activity and inhibit various stages of viral replication, depending on the molecular structure. Wild plants and foods closely related to the original species contain many natural compounds such as phytochemicals, and exhibit various viral growth inhibitory effects. These natural products provide useful information for future antiviral strategies.

Priming of Citrullus lanatus var. Colocynthoides seeds in seaweed extract improved seed germination, plant growth and performance under salinity conditions

Citrullus lanatus var. Colocynthoide “Gurum” is an unconventional crop that can be utilized as a new source of edible oil and has the ability to grow in a variety of harsh conditions. To mitigate the adverse effects of salinity on seed germination and plant performance of C. lanatus, seeds were primed in the aqueous extracts of the seaweed Ulva lactuca before planting under greenhouse conditions. The aqueous extract of U. lactuca at 8% w/v led to maximal seed germination percentage and seedling growth of C. lanatus. Moreover, U. lactuca extract counteracted the negative effects of salt stress on the plant by significantly increasing the activity of SOD, CAT, and POD. The bioactive components of U. lactuca, e.g. glycine betaine and phenolic compounds can account for such beneficial role of algal extract on C. lanatus. Thus, priming of C. lanatus seeds in U. lactuca extract with various concentrations of U. lactuca extract can be employed as an effective practice for successful seed germination, improved plant growth and enhanced salt resistance, probably as a result of increased antioxidant enzymes activity and photosynthetic pigments.

Polyphenolic profiling and analgesic activity of Citrullus lanatus var. citroides fruit

Polyphenolic profiling and analgesic activity of Citrullus lanatus var. citroides fruit

A meta-analysis on rootstock-induced effects in grafted watermelon (Citrullus lanatus var. lanatus)

Sweet watermelon (Citrullus lanatus var. lanatus) grafting with complementary rootstocks is necessary for new variety design and to enhance product profiles, including fruit yield and quality and tolerance to biotic and abiotic stresses.. Integrated selection of successful watermelon grafts using multiple traits ensures breeding and economic gains. Therefore, the objective of this study was to undertake a meta-analysis on the responses of watermelon when grafted with contrasting rootstocks involving cucurbit species or interspecific hybrids using agronomic, physiological and quality traits, and insect pest and disease reactions for rootstock selection, variety development and deployment. A meta-analysis was conducted involving 65 studies, and data were analysed using various statistical methods. Results indicated significant (p < 0.05) variations among watermelon varieties for economic traits when grafted onto different cucurbit rootstock species. Interspecific hybrid [Cucurbita maxima × C. moschata] and Lagenaria siceraria (Molina) Standl rootstocks induced high and variable effects on fruit yield and related traits of grafted watermelon.. Watermelon/L. siceraria graft combinations showed high phenotypic variation on sugar profiles. Lycopene content of grafted watermelon was highly variable when grafted onto C. lanatus var. citroides and C. maxima × C. moschata rootstocks. Graft combinations involving L. siceraria and C. maxima × C. moschata were significantly (p < 0.05) differentiated for fruit flesh firmness and color. C. lanatus var. citroides rootstock enhanced low and variable infections for root-knot nematodes, whereas C. maxima × C. moschata rootstock induced high and variable resistance to Fusarium and Verticillium wilt in grafted watermelon. Fruit yield and quality traits of grafted watermelon positively and significantly (p <0.05; p <0.001) correlated with root and photosynthetic parameters useful in selection programs. Overall, the meta-analysis revealed the need to integrate root traits (e.g., increased root weight and total root length, higher root surface area and average root diameter), high photosynthetic efficiency, fruit yield and quality in selecting desirable rootstock in the development of market preferred watermelon varieties.

Determination of the Microspore Development Concerning Floral Morphology for Improving Drought Tolerant Citron Watermelon (Citrullus lanatus var. citroides) Rootstocks Via Androgenesis.

The negative effects of abiotic stress factors (especially drought and salinity) that arise due to global climate change are increasing in today’s agricultural production. To eliminate the negative effects of these stress factors, some cultural practices have been implemented such as the breeding of tolerant cultivars and rootstock, exogenous applications of PGPR, AMF, and chemical substances, etc. Contrary to exogenous applications, providing tolerance with breeding methods has an important role in efficient and sustainable agriculture. Androgenesis is a phenomenon for the induction and development of microspore-derived pure lines, as initial material for F1 cultivar breeding, in different vegetable crops. Success in microspore embryogenesis is considerably related to the culture of microspores at an appropriate developmental stage. There is no standard protocol for the anther culture in citron watermelon (Citrullus lanatus var. citroides). Thus, a relation between floral morphology (bud length and width, bud index, sepal position, petal color), and microspore development (microspore diameter, uninucleated and binucleated phases) was investigated in citron. The male flower buds were collected at different sizes and microspore development was observed in both light and fluorescence microscopy. A strong positive relationship was detected between flower bud morphology and the specific stages of microspore development. To the author’s knowledge, this is the first report to indicate that the microspore developmental stage can be estimated by flower bud morphology, and applied in the anther/microspore culture of citron watermelon.

Comparative Analysis of Traditional Oriental Herbal Fruits as Potential Sources of Polyphenols and Minerals for Nutritional Supplements.

There are a plethora of plant species in India, which have been widely used in vegetable dishes, soups, desserts and herbal medicine. In addition to these traditional uses, today there is the extra possibility of also being able to use these plants in the nutritional supplements industry due to their favorable antioxidant and mineral composition. In this sense, thirteen vegetable species-Chanania lanzan, Ziziphus mauritiana, Nilumbo nucifera, Terminalia catappa, Terminalia arjuna, Terminalia bellirica, Terminalia chebula, Lagenaria siceraria, Luffa aegyptiaca, Praecitrullus fistulosus, Benincasa hispida, Citrullus lanatus var. lanatus and Cucurbita maxima-have been analyzed. In this paper we discuss the distribution of polyphenols and minerals (Na, K, Mg, Ca, Al, P, S, Cr, Mn, Fe, Cu, Zn, Mo, As and Pb) in different seed parts (the rhizome, pericarp, carpel, seed coat and kernel) of the above species and their possible use in the nutritional supplements industry. The concentrations of total polyphenols, flavonoids and minerals ranged from 407 to 3144 mg rutin hydrate/100 g, 24 to 3070 mg quercetin/100 g and 1433 to 7928 mg/100 g, respectively. K, Ca, P and S were abundant in these herbal fruits. In two species of herbal fruits, Terminalia arjuna and Terminalia chebula, only part of the seed structure was suitable for use in nutritional supplements.

Grafting improves the growth and yield of Cucumis sativus plants grown under salinity stresses by modulating antioxidant enzymes, water status and nutrient uptake

The purpose of this research was to determine if salt-tolerant rootstock could be used to increase cucumber yield and quality in saline environments. Greenhouse experiments were conducted for 2020 and 2021, with five salt stress-tolerant rootstocks (Super Green (squash hybrid, Modesto seeds company, Modesto, California 95357, U.S.A.), Just (squash hybrid, American Takii seeds, California, U.S.A.), bottle gourd 1 (Legenaria siceraria, PI 491352), bottle gourd 2 (Legenaria siceraria, PI 491365), watermelon (Citrullus lanatus var. Colocynthoides), and Laurens (cucumber cultivar, Enza Zaden, Enkhuizen, Netherlands) and salt-sensitive genotypes of Luerans (scion). Specimens of these genotypes were subjected to distinct salinity levels of 0, 50, 100, and 150 mM (NaCl). The morphophysiological responses of these genotypes to salt stress were evaluated. Under normal and stressful conditions, the plant height, leaf area (LA), leaf water content (LWC), number of leaves, root dry matter, shoot dry matter, rates of leaf appearance and stem elongation, fruit yield, and quality increased significantly in grafted cucumber plants compared with non-grafted individuals (control). Similar findings were noted in the physiological properties of antioxidant enzymes, proline content, and leaf nutrient concentration (N, P, K, Ca, Mg, Fe, Zn, and Na). Grafting of Luerans on five rootstocks significantly elevated the antioxidant enzymes (catalase and peroxidase) activity level, increased proline accumulation, and reduced leaf sodium (Na) content.

Citron melon peel flours: drying kinetics and physicochemical evaluation

In the utilization of citron melon (Citrullus lanatus var. citroides), it is necessary to deal with a large amount of residues constituted by the peels. These materials commonly discarded can be fully utilized, since they are a source of nutrients. The peels contain not only fibers, but also proteins, sugars and minerals, which, after drying, are concentrated to values that make them interesting for various uses, including for the enrichment of flours or combinations to prepare bakery products. Therefore, the drying of the peels, besides enabling the conservation and storage at room temperature, expands the forms of use and the possibilities of entering the production chain. This study aimed to characterize physico-chemically and determine drying kinetics, effective diffusivity, activation energy and thermodynamic properties of citron melon peels at different drying temperatures. The peels were dried in an oven with forced air circulation, in a thin layer, at temperatures of 60, 70, 80 and 90 °C. With the data collected in the drying, the drying kinetic curves were constructed and eleven mathematical models were fitted to the experimental data. The dried material was crushed in a knife mill and characterized for physicochemical parameters. Midilli model resulted in the best fits, followed by Page and Approximation of Diffusion models. Effective diffusivity increased with drying temperature; activation energy was obtained from the Arrhenius equation and was equal to 8.18 kJ/mol. Enthalpy and entropy were reduced with increased temperature, while Gibbs free energy increased.

Evaluation of rootstocks resistant to gummy stem blight and their effect on the fruit yield and quality traits of grafted watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai)

ABSTRACT Three gummy stem blight (GSB) resistant watermelon (Citrullus lanatus var. citroides) genotypes (IIHR-82, IIHR-617 and BIL-53), two resistant bottle gourd (Lagenaria siceraria) genotypes (BG-95, BG-77-6-1) and three hybrid combinations based on watermelon genotypes (IIHR-617 × Arka Manik, IIHR-82 × Arka Manik and IIHR-82 × IIHR-617) were evaluated as rootstocks for yield, quality and GSB incidence in a sick plot during spring 2019, spring 2020 and spring 2021 at Indian Institute of Horticultural Research, Bangalore. The commercial watermelon hybrid NS-295 was used as a scion for grafting onto these rootstocks. Significant differences were observed among the grafted entries and checks in terms of disease incidence (PDI). Among agronomic traits, grafting significantly affected plant growth, earliness and yield in a desirable direction. The grafted scion onto the hybrid rootstocks and BG-95 could maintain its oblong fruit shape compared to those onto IIHR-82 and BIL-53, whereas BG-77-6-1 produced spherical fruits. Quality traits showed an improvement in terms of total soluble solids (TSS), flesh colour, total carotenoids and lycopene content among the grafted entries as compared to non-grafted controls. Overall, the use of hybrid rootstocks i.e. IIHR-82 × IIHR-617 and IIHR-82 × Arka Manik was found to be advantageous in managing GSB apart from imparting desirable agronomic and fruit quality traits.

Rootstock potential of auto and Allotetraploid Citron [Citrullus lanatus var. citroides (L. H. Bailey) Mansf.] for Watermelon [Citrullus lanatus var lanatus (Thunb.) Matsum. &amp; Nakai] under hydroponic conditions: plant growth and some physiological characteristics

The emergence of some physiological and fruit quality problems due to the common squash rootstocks used in watermelon has led researchers to search for alternative rootstocks sources. Exploitation of novel Citrullus germplasm such as citronmelon (Citrullus lanatus var. citroides) is an alternative to avoid these problems. In this study, rootstocks potential of auto and allotetraploid citrullus genotypes for watermelon were investigated as regard to plant growth and some physiological parameters under hyroponic conditions. Plant length was significantly affected by rootstock genotype and the longest plant stem was measured in watermelon plants grafted on N7-4T tetraploid rootstock (62.67 cm) while the shortest stem was measured in grafted plants onto autotetraploid Calhounn Gray with 14.33 cm. Among the graft combinations, N7-4T/CT (93.33 g) and CN7-5T/CT 95.00 g) graft combination produced the highest shoot fresh and dry weight. As in shoot fresh weight, the exploitationted on to tetraploid rootstock produced higher root fresh and dry weight than the plants grafted on diploid rootstocks and commercial rootstock. The highest root fresh and dry weight were determined in the plants grafted on to autotetraploid N5-4T and allotetraploid CN7-5T. Root characteristics were significantly affected by rootstock genotypes. The N, P, K and Ca contents of the leaves of the CT watermelon cultivar grafted on different rootstocks were significantly affected by the rootstocks. This study showed that citrullus tetraploid genotypes (auto and allo) to be produced by polyploidy method can be an important alternative rootstock source for watermelon.

Phytochemical analysis and antibacterial activity of Citrullus lanatus var. citroides (Citron watermelon) fruit and the effect of temperature on the biological activity of the rind

The use of indigenous plants for food, water and medicinal purposes dates back to decades of years. In southern Africa the fruit flesh and rind of Citrullus lanatus var. citroides are cooked as porridge with maize meal and served to sick people by traditional healers. The seeds are dried, roasted and eaten as nuts or ground into flour to make bread. The aim of this study was to determine the biological activities of the seed and flesh of Citrullus lanatus var. citroides fruit and evaluate the effect of temperature on rind bioactivity. The rind was exposed to various temperatures. Total phenolics, tannins, flavonoids, nutritional content and antioxidant activity were estimated using spectrometric methods. Antibacterial activity was determined using micro-broth dilution and bioautography. Total polyphenolic contents were greatest in the seeds, followed by the flesh and rind respectively. Potassium was the most abundant element present in the flesh, seeds and untreated rind control. The flesh had higher antioxidant activity than the rind and seeds. Pseudomonas aeruginosa was the most susceptible pathogen for both the seeds and flesh where minimum inhibitory concentrations between 0.02–0.31 mg/mL were determined. High temperatures led to a significant loss in rind bioactivity. Lower temperatures must be considered when preparing C. lanatus var. citroides products to preserve the potential therapeutic properties which supplement its nutritional content.

Phenotypic Variability of Root System Architecture Traits for Drought Tolerance among Accessions of Citron Watermelon (Citrullus lanatus var. citroides (L.H. Bailey).

Citron watermelon (Citrullus lanatus var. citroides) is a drought-tolerant cucurbit crop widely grown in sub-Saharan Africa in arid and semi-arid environments. The species is a C3 xerophyte used for multiple purposes, including intercropping with maize, and has a deep taproot system. The deep taproot system plays a key role in the species’ adaptation to dry conditions. Understanding the root system development of this crop could be useful to identify traits for breeding water-use efficient and drought-tolerant varieties. This study compared the root system architecture of citron watermelon accessions under water-stress conditions. Nine selected and drought-tolerant citron watermelon accessions were grown under non-stress (NS) and water stress (WS) conditions using the root rhizotron procedure in a glasshouse. The following root system architecture (RSA) traits were measured: root system width (RSW), root system depth (RSD), convex hull area (CHA), total root length (TRL), root branch count (RBC), total root volume (TRV), leaf area (LA), leaf number (LN), first seminal root length (FSRL), seminal root angle (SRA), root dry mass (RDM), shoot dry mass (SDM), root–shoot mass ratio (RSM), root mass ratio (RMR), shoot mass ratio (SMR) and root tissue density (RTD). The data collected on RSA traits were subjected to an analysis of variance (ANOVA), correlation and principal component analyses. ANOVA revealed a significant (p < 0.05) accession × water stress interaction effect for studied RSA traits. Under WS, RDM exhibited significant and positive correlations with RSM (r = 0.65), RMR (r = 0.66), RSD (r = 0.66), TRL (r = 0.60), RBC (r = 0.72), FSRL (r = 0.73) and LN (r = 0.70). The principal component analysis revealed high loading scores for the following RSA traits: RSW (0.89), RSD (0.97), TRL (0.99), TRV (0.90), TRL (0.99), RMR (0.96) and RDM (0.76). In conclusion, the study has shown that the identified RSA traits could be useful in crop improvement programmes for citron watermelon genotypes with enhanced drought adaptation for improved yield performance under drought-prone environments.

Influence of grafting on fatty acid profile and some physicochemical properties of watermelon seed and seed oil

This study aimed to investigate the effects of grafting on the fatty acid profile and some physicochemical properties of watermelon seed and seed oil. The ‘Crimson Tide’ cultivar was used as the scion while two wild watermelon (Citrullus lanatus var. citroides (A1 and A2)), one Lagenaria siceraria (A3) and one Cucurbita maxima Duchesne x Cucurbita moschata Duchesne (A4) were used as rootstocks. The use of rootstock significantly influenced the fatty acid profile and the physical parameters of seeds and seed oils. The highest linoleic acid ratio was found in the seed oil from A1 and A2, the oil from A3 had the highest oleic acid ratio. The results showed that the content and acid value in seed oils were improved, and that total phenolic compounds and antioxidant activity of both seed and oil were decreased by grafting. Wild rootstocks can be used in watermelon cultivation to obtain a watermelon seed which is rich in linoleic acid.

Characterization of genetic diversity of citron watermelon landrace accessions of South Africa through simple sequence repeat markers

ABSTRACT Profiling the genetic diversity of germplasm collections is fundamental for selection programs and strategic conservation. Citron watermelon (Citrullus lanatus var. citroides [L.H. Bailey] Mansf. ex Greb.) is an under-researched cucurbit crop despite providing food and nutritional security in sub-Saharan Africa. There is limited information on genetic relationships of South African citron watermelon accessions for effective breeding. The objective of this study was to determine the extent of genetic diversity among 48 South African citron watermelon landrace accessions using selected simple sequence repeat (SSR) markers to identify genetically divergent accessions for trait integration and variety development. The SSR markers amplified a total of 24 alleles, with a mean expected heterozygosity value of 0.38, indicating moderate genetic diversity among the studied accessions. The mean polymorphic information content value of 0.21 indicated low discriminatory power of the SSR markers. Analysis of molecular variance attributed 8%, 75%, and 17% of the molecular variation between populations, among accessions and within accessions, respectively. Three distinctive genetic groups were identified based on cluster analysis, which aided the selection of genetically diverse citron watermelon accessions for breeding and cultivar development.

Genetic analysis of yield related traits in landrace × commercial watermelon hybrids

Watermelon [Citrullus lanatus var lanatus L.] is a major xerophytic crop originating in Africa especially grown in subtropical and tropical parts of the world. However, few adapted varieties are available to promote greater yield and make watermelon a viable commercial crop of choice. Path analysis and combining ability was carried out for yield related traits among three popular local landraces; Landrace1, Landrace 2 and Landrace 3 collected in Zimbabwe and three commercial watermelon varieties ‘Congo’, ‘Charleston Grey’ and ‘Crimson Sweet’ in plots arranged in an RCBD replicated 3 times. A complete diallel mating design was used to generate 36 F1 genotypes which together with the parents were evaluated for several quantitate traits. Data on correlations, path analysis, GCA and SCA between fruit yield and other traits were computed using Microsoft Excel and GenStat 17. Individual fruit weight (FIW) and the number of fruits per plant (NF) were found to be significantly linked with final fruit yield. Significant positive correlations were also observed on NF and number of female flowers (NFF), number of vines (NV), and FIW and these traits could be recommended as reliable selection indicators for creating high yielding watermelon genotypes. Path analysis showed that FIW and NF were the most important contributors to watermelon yield. GCA and SCA effects were significant and positive for yield which indicates that the traits are controlled by both additive and non-additive genes. ‘Crimson Sweet’ and ‘Landrace 1’ were the best pollen sources whereas ‘Landrace 1’ and ‘Landrace 2’ were the highest yielders when used as female parents. Overall, results from this study identified usable yield related proxies and need to incorporate local landraces germplasm in watermelon improvement.

Influenza virus entry and replication inhibited by 8-prenylnaringenin from Citrullus lanatus var. citroides (wild watermelon).

We previously demonstrated the anti‐influenza activity of Citrullus lanatus var. citroides (wild watermelon, WWM); however, the active ingredient was unknown. Here, we performed metabolomic analysis to evaluate the ingredients of WWM associated with antiviral activity. Many low‐molecular weight compounds were identified, with flavonoids accounting for 35% of all the compounds in WWM juice. Prenylated flavonoids accounted for 30% of the flavonoids. Among the measurable components of phytoestrogens in WWM juice, 8‐prenylnaringenin showed the highest antiviral activity. We synthesized 8‐prenylnaringenin and used liquid chromatography–mass spectrometry to quantitate the active ingredient in WWM. The antiviral activities of 8‐prenylnaringenin were observed against H1N1 and H3N2 influenza A subtypes and influenza B viruses. Moreover, 8‐prenylnaringenin was found to inhibit virus adsorption and late‐stage virus replication, suggesting that the mechanisms of action of 8‐prenylnaringenin may differ from those of amantadine and oseltamivir. We confirmed that 8‐prenylnaringenin strongly inhibited the viral entry of all the influenza virus strains that were examined, including those resistant to the anti‐influenza drugs oseltamivir and amantadine. This result indicates that 8‐prenylnaringenin may activate the host cell's defense mechanisms, rather than directly acting on the influenza virus. Since 8‐prenylnaringenin did not inhibit late‐stage virus replication of oseltamivir‐resistant strains, 8‐prenylnaringenin may interact directly with viral neuraminidase. These results are the first report on the anti‐influenza virus activity of 8‐prenylnaringenin. Our results highlight the potential of WWM and phytoestrogens to develop effective prophylactic and therapeutic approaches to the influenza virus.

Constrains in commercialization of watermelon (Citrullus lanatus) Cultivation in Africa—A review

Watermelon, [Citrullus lanatus var. lanatus L] is a major crop in Africa, especially facing the harsh effects of climatic change. It is a xerophytic crop that can be grown in subtropical and tropical parts of the world. Some constrains in commercialization of watermelon production are related to agronomic practices, post-harvest management and value-addition in Africa. Several products can be made from watermelon seeds, rind as well as their pulp, thereby boosting the food industry through its materials. However, watermelon production in Africa is hindered by several constrains, like weeds, pests, diseases and poor post-harvesting management. For the realization of true potential of watermelon production in Africa, more research is needed to come up with varieties which are tolerant to pests, diseases and weeds. The awareness in communities on its importance as a commercial crop in drought-prone areas also need attention.